Refine guides (#6741)

docs/en/guides/E2E-local-remote-debug.md

 # Using E2E local remote debugging
 The E2E remote debugging port of service containers is `5005`. If the developer wants to use remote debugging, he needs to add remote debugging parameters to the start service command, and then expose the port `5005`. 
 
-For example, this is the configuration of a container in the [skywalking/test/e2e/e2e-test/docker/base-compose.yml](https://github.com/apache/skywalking/blob/master/test/e2e/e2e-test/docker/base-compose.yml). [JAVA_OPTS](https://github.com/apache/skywalking/blob/190ca93b6bf48e9d966de5b05cd6490ba54b7266/docker/oap/docker-entrypoint.sh) is a preset variable for passing additional parameters in the AOP service startup command, so we only need to add the JAVA remote debugging parameters `agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005` to the configuration and exposes the port `5005`.
+For example, this is the configuration of a container in [skywalking/test/e2e/e2e-test/docker/base-compose.yml](https://github.com/apache/skywalking/blob/master/test/e2e/e2e-test/docker/base-compose.yml). [JAVA_OPTS](https://github.com/apache/skywalking/blob/190ca93b6bf48e9d966de5b05cd6490ba54b7266/docker/oap/docker-entrypoint.sh) is a preset variable for passing additional parameters in the AOP service startup command, so we only need to add the JAVA remote debugging parameters `agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005` to the configuration and expose the port `5005`.
 ```yml
 oap:
     image: skywalking/oap:latest
@@ -16,7 +16,7 @@ oap:
         -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005
     ...
 ```
-At last, if the E2E test failed and is retrying, the developer can get the ports mapping in the file `skywalking/test/e2e/e2e-test/remote_real_port` and selects the host port of the corresponding service for remote debugging. For example,
+At last, if the E2E test fails and is retrying, the developer may get the ports mapping in the file `skywalking/test/e2e/e2e-test/remote_real_port` and select the host port of the corresponding service for remote debugging. For example,
 ```bash
 #remote_real_port
 
@@ -25,4 +25,4 @@ oap-localhost:32783
 
 #The remote debugging port on the host is 32782
 provider-localhost:32782 
-```
+```
\ No newline at end of file

docs/en/guides/How-to-build.md

-# How to build project
-This document helps people to compile and build the project in your maven and set your IDE.
+# How to build a project
+This document will help you compile and build a project in your maven and set your IDE.
 
-## Build Project
-**Because we are using Git submodule, we recommend don't use `GitHub` tag or release page to download source codes for compiling.**
+## Building the Project
+**Since we are using Git submodule, we do not recommend using the `GitHub` tag or release page to download source codes for compiling.**
 
-### Maven behind Proxy
-If you need to execute build behind the proxy, edit the *.mvn/jvm.config* and put the follow properties:
+### Maven behind the Proxy
+If you need to execute build behind the proxy, edit the *.mvn/jvm.config* and set the follow properties:
 ```properties
 -Dhttp.proxyHost=proxy_ip
 -Dhttp.proxyPort=proxy_port
@@ -15,11 +15,11 @@ If you need to execute build behind the proxy, edit the *.mvn/jvm.config* and pu
 -Dhttp.proxyPassword=password
 ```
 
-### Build from GitHub
-1. Prepare git, JDK8+ and Maven 3.6+
-1. Clone project
+### Building from GitHub
+1. Prepare git, JDK8+, and Maven 3.6+.
+1. Clone the project.
 
-    If you want to build a release from source codes, provide a `tag name` by using `git clone -b [tag_name] ...` while cloning.
+    If you want to build a release from source codes, set a `tag name` by using `git clone -b [tag_name] ...` while cloning.
     
     ```bash
     git clone --recurse-submodules https://github.com/apache/skywalking.git
@@ -36,18 +36,18 @@ If you need to execute build behind the proxy, edit the *.mvn/jvm.config* and pu
 1. Run `./mvnw clean package -DskipTests`
 1. All packages are in `/dist` (.tar.gz for Linux and .zip for Windows).
 
-### Build from Apache source code release
-- What is `Apache source code release`?
+### Building from Apache source code release
+- What is the `Apache source code release`?
 
-For each official Apache release, there is a complete and independent source code tar, which is including all source codes. You could download it from [SkyWalking Apache download page](http://skywalking.apache.org/downloads/). No git related stuff required when compiling this. Just follow these steps.
+For each official Apache release, there is a complete and independent source code tar, which includes all source codes. You could download it from [SkyWalking Apache download page](http://skywalking.apache.org/downloads/). There is no requirement related to git when compiling this. Just follow these steps.
 
-1. Prepare JDK8+ and Maven 3.6+
-1. Run `./mvnw clean package -DskipTests`
+1. Prepare JDK8+ and Maven 3.6+.
+1. Run `./mvnw clean package -DskipTests`.
 1. All packages are in `/dist`.(.tar.gz for Linux and .zip for Windows).
 
-### Advanced compile
-SkyWalking is a complex maven project, including many modules, which could cause long compiling time. 
-If you just want to recompile part of the project, you have following options
+### Advanced compiling
+SkyWalking is a complex maven project that has many modules. Therefore, the time to compile may be a bit longer than usual.
+If you just want to recompile part of the project, you have the following options:
 - Compile agent and package
 >  ./mvnw package -Pagent,dist
 
@@ -55,7 +55,7 @@ or
 
 > make build.agent
 
-If you intend to compile a single one plugin, such as in the dev stage, you could
+If you intend to compile a single plugin, such as one in the dev stage, you could
 >  cd plugin_module_dir & mvn clean package
 
 - Compile backend and package
@@ -73,16 +73,16 @@ or
 > make build.ui
 
 
-### Build docker images
-We can build docker images of `backend` and `ui` with `Makefile` located in root folder.
+### Building docker images
+You can build docker images of `backend` and `ui` with `Makefile` located in root folder.
 
 Refer to [Build docker image](../../../docker) for more details.
 
-## Setup your IntelliJ IDEA
-**NOTICE**: If you clone the codes from GitHub, please make sure that you had finished step 1 to 3 in section **[Build from GitHub](#build-from-github)**, if you download the source codes from the official website of SkyWalking, please make sure that you had followed the steps in section **[Build from Apache source code release](#build-from-apache-source-code-release)**.
+## Setting up your IntelliJ IDEA
+**NOTE**: If you clone the codes from GitHub, please make sure that you have finished steps 1 to 3 in section **[Build from GitHub](#build-from-github)**. If you download the source codes from the official website of SkyWalking, please make sure that you have followed the steps in section **[Build from Apache source code release](#build-from-apache-source-code-release)**.
 
-1. Import the project as a maven project
-1. Run `./mvnw compile -Dmaven.test.skip=true` to compile project and generate source codes. Because we use gRPC and protobuf.
+1. Import the project as a maven project.
+1. Run `./mvnw compile -Dmaven.test.skip=true` to compile project and generate source codes. The reason is that we use gRPC and protobuf.
 1. Set **Generated Source Codes** folders.
     * `grpc-java` and `java` folders in **apm-protocol/apm-network/target/generated-sources/protobuf**
     * `grpc-java` and `java` folders in **oap-server/server-core/target/generated-sources/protobuf**