Fix broken links to the correct page (#1726)

* Fix broken links to the correct page.

* Direct getting started links to the correct doc

apm-dist/release-docs/README.txt

@@ -20,10 +20,10 @@ Getting Started
 To help you get started, try the following links:
 
 Getting Started
-    https://github.com/apache/incubator-skywalking/blob/master/docs/en/Quick-start.md
+    https://github.com/apache/incubator-skywalking/blob/master/docs/en/setup/README.md
 
 Building
-    https://github.com/apache/incubator-skywalking/blob/master/docs/en/How-to-build.md
+    https://github.com/apache/incubator-skywalking/blob/master/docs/en/guides/How-to-build.md
 
 We welcome contributions of all kinds, for details of how you can help
     https://github.com/apache/incubator-skywalking/blob/master/CONTRIBUTING.md
@@ -31,10 +31,6 @@ We welcome contributions of all kinds, for details of how you can help
 Find the issue tracker from here
     https://github.com/apache/incubator-skywalking/issues
 
-Find our roadmap
-    https://github.com/apache/incubator-skywalking/blob/master/docs/ROADMAP.md
-
-
 Please help us make Apache SkyWalking better - we appreciate any feedback
 you may have.
 
@@ -46,4 +42,4 @@ Licensing
 ===============================================================================
 
 This software is licensed under the terms you may find in the file
-named "LICENSE" in this directory.
\ No newline at end of file
+named "LICENSE" in this directory.

docs/en/setup/service-agent/java-agent/Quick-start.md

-# Quick start
-Quick start is for end users to start up the SkyWalking quickly in local.
-
-1. Download releases from Apache official website. [Link](http://skywalking.apache.org/downloads/)
-1. Deploy backend on local. See [collector in standalone mode doc](Deploy-backend-in-standalone-mode.md)
-1. Install Java Agent. [Doc](Deploy-skywalking-agent.md)
-1. Set your OS time(include time zone) correct.
-1. Reboot your applications, and open UI.
-1. Default username/password for the login page is `admin/admin`.
-
-If you want to deploy SkyWalking in server or cloud as a cluster, please following these two documents:
-1. [Install javaagent](Deploy-skywalking-agent.md)
-1. [Deploy backend in cluster mode](Deploy-backend-in-cluster-mode.md)
\ No newline at end of file