[SPARK-39677][SQL][DOCS][3.2] Fix args formatting of the regexp and like functions

### What changes were proposed in this pull request?
In the PR, I propose to fix args formatting of some regexp functions by adding explicit new lines. That fixes the following items in arg lists.

Before:

<img width="745" alt="Screenshot 2022-07-05 at 09 48 28" src="https://user-images.githubusercontent.com/1580697/177274234-04209d43-a542-4c71-b5ca-6f3239208015.png">

After:

<img width="704" alt="Screenshot 2022-07-05 at 11 06 13" src="https://user-images.githubusercontent.com/1580697/177280718-cb05184c-8559-4461-b94d-dfaaafda7dd2.png">

### Why are the changes needed?
To improve readability of Spark SQL docs.

### Does this PR introduce _any_ user-facing change?
No.

### How was this patch tested?
By building docs and checking manually:
```
$ SKIP_SCALADOC=1 SKIP_PYTHONDOC=1 SKIP_RDOC=1 bundle exec jekyll build
```

Authored-by: Max Gekk <max.gekkgmail.com>
Signed-off-by: Max Gekk <max.gekkgmail.com>
(cherry picked from commit 4e42f8b)
Signed-off-by: Max Gekk <max.gekkgmail.com>

Closes #37093 from MaxGekk/fix-regexp-docs-3.2.

Authored-by: Max Gekk <[email protected]>
Signed-off-by: Max Gekk <[email protected]>

Author: MaxGekk

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/regexpExpressions.scala

@@ -83,16 +83,12 @@ abstract class StringRegexExpression extends BinaryExpression
     Arguments:
       * str - a string expression
       * pattern - a string expression. The pattern is a string which is matched literally, with
-          exception to the following special symbols:
-
-          _ matches any one character in the input (similar to . in posix regular expressions)
-
+          exception to the following special symbols:<br><br>
+          _ matches any one character in the input (similar to . in posix regular expressions)\
           % matches zero or more characters in the input (similar to .* in posix regular
-          expressions)
-
+          expressions)<br><br>
           Since Spark 2.0, string literals are unescaped in our SQL parser. For example, in order
-          to match "\abc", the pattern should be "\\abc".
-
+          to match "\abc", the pattern should be "\\abc".<br><br>
           When SQL config 'spark.sql.parser.escapedStringLiterals' is enabled, it falls back
           to Spark 1.6 behavior regarding string literal parsing. For example, if the config is
           enabled, the pattern to match "\abc" should be "\abc".
@@ -352,12 +348,10 @@ case class NotLikeAny(child: Expression, patterns: Seq[UTF8String]) extends Like
   arguments = """
     Arguments:
       * str - a string expression
-      * regexp - a string expression. The regex string should be a Java regular expression.
-
+      * regexp - a string expression. The regex string should be a Java regular expression.<br><br>
           Since Spark 2.0, string literals (including regex patterns) are unescaped in our SQL
           parser. For example, to match "\abc", a regular expression for `regexp` can be
-          "^\\abc$".
-
+          "^\\abc$".<br><br>
           There is a SQL config 'spark.sql.parser.escapedStringLiterals' that can be used to
           fallback to the Spark 1.6 behavior regarding string literal parsing. For example,
           if the config is enabled, the `regexp` that can match "\abc" is "^\abc$".
@@ -505,12 +499,10 @@ case class StringSplit(str: Expression, regex: Expression, limit: Expression)
     Arguments:
       * str - a string expression to search for a regular expression pattern match.
       * regexp - a string representing a regular expression. The regex string should be a
-          Java regular expression.
-
+          Java regular expression.<br><br>
           Since Spark 2.0, string literals (including regex patterns) are unescaped in our SQL
           parser. For example, to match "\abc", a regular expression for `regexp` can be
-          "^\\abc$".
-
+          "^\\abc$".<br><br>
           There is a SQL config 'spark.sql.parser.escapedStringLiterals' that can be used to
           fallback to the Spark 1.6 behavior regarding string literal parsing. For example,
           if the config is enabled, the `regexp` that can match "\abc" is "^\abc$".
@@ -707,12 +699,10 @@ abstract class RegExpExtractBase
     Arguments:
       * str - a string expression.
       * regexp - a string representing a regular expression. The regex string should be a
-          Java regular expression.
-
+          Java regular expression.<br><br>
           Since Spark 2.0, string literals (including regex patterns) are unescaped in our SQL
           parser. For example, to match "\abc", a regular expression for `regexp` can be
-          "^\\abc$".
-
+          "^\\abc$".<br><br>
           There is a SQL config 'spark.sql.parser.escapedStringLiterals' that can be used to
           fallback to the Spark 1.6 behavior regarding string literal parsing. For example,
           if the config is enabled, the `regexp` that can match "\abc" is "^\abc$".
@@ -812,12 +802,10 @@ case class RegExpExtract(subject: Expression, regexp: Expression, idx: Expressio
     Arguments:
       * str - a string expression.
       * regexp - a string representing a regular expression. The regex string should be a
-          Java regular expression.
-
+          Java regular expression.<br><br>
           Since Spark 2.0, string literals (including regex patterns) are unescaped in our SQL
           parser. For example, to match "\abc", a regular expression for `regexp` can be
-          "^\\abc$".
-
+          "^\\abc$".<br><br>
           There is a SQL config 'spark.sql.parser.escapedStringLiterals' that can be used to
           fallback to the Spark 1.6 behavior regarding string literal parsing. For example,
           if the config is enabled, the `regexp` that can match "\abc" is "^\abc$".