[Issue 3009][docs] Add presto sql REST APIs doc (#5376)

Fixes #3009

*Motivation*

There are no REST APIs usage docs for the presto SQL.

site2/docs/sql-rest-api.md

+---
+id: sql-rest-api
+title: Pulsar SQL REST APIs
+sidebar_label: REST APIs
+---
+
+This section lists resources that make up the Presto REST API v1. 
+
+## Request for Presto services
+
+All requests for Presto services should use Presto REST API v1 version. 
+
+To request services, use explicit URL `http://presto.service:8081/v1`. You need to update `presto.service:8081` with your real Presto address before sending requests.
+
+`POST` requests require the `X-Presto-User` header. If you use authentication, you must use the same `username` that is specified in the authentication configuration. If you do not use authentication, you can specify anything for `username`.
+
+```properties
+X-Presto-User: username
+```
+
+For more information about headers, refer to [PrestoHeaders](https://github.com/prestosql/presto/blob/master/presto-client/src/main/java/io/prestosql/client/PrestoHeaders.java).
+
+## Schema
+
+You can use statement in the HTTP body. All data is received as JSON document that might contain a `nextUri` link. If the received JSON document contains a `nextUri` link, the request continues with the `nextUri` link until the received data does not contain a `nextUri` link. If no error is returned, the query completes successfully. If an `error` field is displayed in `stats`, it means the query fails.
+
+The following is an example of `show catalogs`. The query continues until the received JSON document does not contain a `nextUri` link. Since no `error` is displayed in `stats`, it means that the query completes successfully.
+
+```powershell
+➜  ~ curl --header "X-Presto-User: test-user" --request POST --data 'show catalogs' http://localhost:8081/v1/statement
+{
+   "infoUri" : "http://localhost:8081/ui/query.html?20191113_033653_00006_dg6hb",
+   "stats" : {
+      "queued" : true,
+      "nodes" : 0,
+      "userTimeMillis" : 0,
+      "cpuTimeMillis" : 0,
+      "wallTimeMillis" : 0,
+      "processedBytes" : 0,
+      "processedRows" : 0,
+      "runningSplits" : 0,
+      "queuedTimeMillis" : 0,
+      "queuedSplits" : 0,
+      "completedSplits" : 0,
+      "totalSplits" : 0,
+      "scheduled" : false,
+      "peakMemoryBytes" : 0,
+      "state" : "QUEUED",
+      "elapsedTimeMillis" : 0
+   },
+   "id" : "20191113_033653_00006_dg6hb",
+   "nextUri" : "http://localhost:8081/v1/statement/20191113_033653_00006_dg6hb/1"
+}
+
+➜  ~ curl http://localhost:8081/v1/statement/20191113_033653_00006_dg6hb/1
+{
+   "infoUri" : "http://localhost:8081/ui/query.html?20191113_033653_00006_dg6hb",
+   "nextUri" : "http://localhost:8081/v1/statement/20191113_033653_00006_dg6hb/2",
+   "id" : "20191113_033653_00006_dg6hb",
+   "stats" : {
+      "state" : "PLANNING",
+      "totalSplits" : 0,
+      "queued" : false,
+      "userTimeMillis" : 0,
+      "completedSplits" : 0,
+      "scheduled" : false,
+      "wallTimeMillis" : 0,
+      "runningSplits" : 0,
+      "queuedSplits" : 0,
+      "cpuTimeMillis" : 0,
+      "processedRows" : 0,
+      "processedBytes" : 0,
+      "nodes" : 0,
+      "queuedTimeMillis" : 1,
+      "elapsedTimeMillis" : 2,
+      "peakMemoryBytes" : 0
+   }
+}
+
+➜  ~ curl http://localhost:8081/v1/statement/20191113_033653_00006_dg6hb/2
+{
+   "id" : "20191113_033653_00006_dg6hb",
+   "data" : [
+      [
+         "pulsar"
+      ],
+      [
+         "system"
+      ]
+   ],
+   "infoUri" : "http://localhost:8081/ui/query.html?20191113_033653_00006_dg6hb",
+   "columns" : [
+      {
+         "typeSignature" : {
+            "rawType" : "varchar",
+            "arguments" : [
+               {
+                  "kind" : "LONG_LITERAL",
+                  "value" : 6
+               }
+            ],
+            "literalArguments" : [],
+            "typeArguments" : []
+         },
+         "name" : "Catalog",
+         "type" : "varchar(6)"
+      }
+   ],
+   "stats" : {
+      "wallTimeMillis" : 104,
+      "scheduled" : true,
+      "userTimeMillis" : 14,
+      "progressPercentage" : 100,
+      "totalSplits" : 19,
+      "nodes" : 1,
+      "cpuTimeMillis" : 16,
+      "queued" : false,
+      "queuedTimeMillis" : 1,
+      "state" : "FINISHED",
+      "peakMemoryBytes" : 0,
+      "elapsedTimeMillis" : 111,
+      "processedBytes" : 0,
+      "processedRows" : 0,
+      "queuedSplits" : 0,
+      "rootStage" : {
+         "cpuTimeMillis" : 1,
+         "runningSplits" : 0,
+         "state" : "FINISHED",
+         "completedSplits" : 1,
+         "subStages" : [
+            {
+               "cpuTimeMillis" : 14,
+               "runningSplits" : 0,
+               "state" : "FINISHED",
+               "completedSplits" : 17,
+               "subStages" : [
+                  {
+                     "wallTimeMillis" : 7,
+                     "subStages" : [],
+                     "stageId" : "2",
+                     "done" : true,
+                     "nodes" : 1,
+                     "totalSplits" : 1,
+                     "processedBytes" : 22,
+                     "processedRows" : 2,
+                     "queuedSplits" : 0,
+                     "userTimeMillis" : 1,
+                     "cpuTimeMillis" : 1,
+                     "runningSplits" : 0,
+                     "state" : "FINISHED",
+                     "completedSplits" : 1
+                  }
+               ],
+               "wallTimeMillis" : 92,
+               "nodes" : 1,
+               "done" : true,
+               "stageId" : "1",
+               "userTimeMillis" : 12,
+               "processedRows" : 2,
+               "processedBytes" : 51,
+               "queuedSplits" : 0,
+               "totalSplits" : 17
+            }
+         ],
+         "wallTimeMillis" : 5,
+         "done" : true,
+         "nodes" : 1,
+         "stageId" : "0",
+         "userTimeMillis" : 1,
+         "processedRows" : 2,
+         "processedBytes" : 22,
+         "totalSplits" : 1,
+         "queuedSplits" : 0
+      },
+      "runningSplits" : 0,
+      "completedSplits" : 19
+   }
+}
+```
+
+> Note
+> 
+> Since the response data is not in sync with the query state from the perspective of clients, you cannot rely on the response data to determine whether the query completes.
+
+For more information about Presto REST API, refer to [Presto HTTP Protocol](https://github.com/prestosql/presto/wiki/HTTP-Protocol).

site2/website/sidebars.json

@@ -50,7 +50,8 @@
     "Pulsar SQL": [
       "sql-overview",
       "sql-getting-started",
-      "sql-deployment-configurations"
+      "sql-deployment-configurations",
+      "sql-rest-api"
     ],
     "Deployment": [
       "deploy-aws",