[MINOR][DOCS] JSON APIs related documentation fixes

## What changes were proposed in this pull request?

This PR proposes corrections related to JSON APIs as below:

- Rendering links in Python documentation
- Replacing `RDD` to `Dataset` in programing guide
- Adding missing description about JSON Lines consistently in `DataFrameReader.json` in Python API
- De-duplicating little bit of `DataFrameReader.json` in Scala/Java API

## How was this patch tested?

Manually build the documentation via `jekyll build`. Corresponding snapstops will be left on the codes.

Note that currently there are Javadoc8 breaks in several places. These are proposed to be handled in https://github.com/apache/spark/pull/17477. So, this PR does not fix those.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17602 from HyukjinKwon/minor-json-documentation.

2 files changed, 2 insertions, 2 deletions

diff --git a/examples/src/main/java/org/apache/spark/examples/sql/JavaSQLDataSourceExample.java b/examples/src/main/java/org/apache/spark/examples/sql/JavaSQLDataSourceExample.java
index 1a7054614b..b66abaed66 100644
--- a/examples/src/main/java/org/apache/spark/examples/sql/JavaSQLDataSourceExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/sql/JavaSQLDataSourceExample.java
@@ -215,7 +215,7 @@ public class JavaSQLDataSourceExample {
     // +------+
 
     // Alternatively, a DataFrame can be created for a JSON dataset represented by
-    // an Dataset[String] storing one JSON object per string.
+    // a Dataset<String> storing one JSON object per string.
     List<String> jsonData = Arrays.asList(
             "{\"name\":\"Yin\",\"address\":{\"city\":\"Columbus\",\"state\":\"Ohio\"}}");
     Dataset<String> anotherPeopleDataset = spark.createDataset(jsonData, Encoders.STRING());
diff --git a/examples/src/main/scala/org/apache/spark/examples/sql/SQLDataSourceExample.scala b/examples/src/main/scala/org/apache/spark/examples/sql/SQLDataSourceExample.scala
index 82fd56de39..ad74da72bd 100644
--- a/examples/src/main/scala/org/apache/spark/examples/sql/SQLDataSourceExample.scala
+++ b/examples/src/main/scala/org/apache/spark/examples/sql/SQLDataSourceExample.scala
@@ -139,7 +139,7 @@ object SQLDataSourceExample {
     // +------+
 
     // Alternatively, a DataFrame can be created for a JSON dataset represented by
-    // an Dataset[String] storing one JSON object per string
+    // a Dataset[String] storing one JSON object per string
     val otherPeopleDataset = spark.createDataset(
       """{"name":"Yin","address":{"city":"Columbus","state":"Ohio"}}""" :: Nil)
     val otherPeople = spark.read.json(otherPeopleDataset)