[WIP][SQL][DOC] Fix incorrect `code` tag

## What changes were proposed in this pull request?
This PR is to fix incorrect `code` tag in `sql-programming-guide.md`

## How was this patch tested?
Manually.

Author: Weiqing Yang <yangweiqing001@gmail.com>

Closes #15941 from weiqingy/fixtag.

docs/sql-programming-guide.md

@@ -1100,7 +1100,7 @@ the following case-sensitive options:
   <tr>
      <td><code>isolationLevel</code></td>
      <td>
-       The transaction isolation level, which applies to current connection. It can be one of <code>NONE<code>, <code>READ_COMMITTED<code>, <code>READ_UNCOMMITTED<code>, <code>REPEATABLE_READ<code>, or <code>SERIALIZABLE<code>, corresponding to standard transaction isolation levels defined by JDBC's Connection object, with default of <code>READ_UNCOMMITTED<code>. This option applies only to writing. Please refer the documentation in <code>java.sql.Connection</code>.
+       The transaction isolation level, which applies to current connection. It can be one of <code>NONE</code>, <code>READ_COMMITTED</code>, <code>READ_UNCOMMITTED</code>, <code>REPEATABLE_READ</code>, or <code>SERIALIZABLE</code>, corresponding to standard transaction isolation levels defined by JDBC's Connection object, with default of <code>READ_UNCOMMITTED</code>. This option applies only to writing. Please refer the documentation in <code>java.sql.Connection</code>.
      </td>
    </tr>
 

sql/core/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala

@@ -108,7 +108,7 @@ object SQLConf {
     .doc("Configures the maximum size in bytes for a table that will be broadcast to all worker " +
       "nodes when performing a join.  By setting this value to -1 broadcasting can be disabled. " +
       "Note that currently statistics are only supported for Hive Metastore tables where the " +
-      "command<code>ANALYZE TABLE &lt;tableName&gt; COMPUTE STATISTICS noscan</code> has been " +
+      "command <code>ANALYZE TABLE &lt;tableName&gt; COMPUTE STATISTICS noscan</code> has been " +
       "run, and file-based data source tables where the statistics are computed directly on " +
       "the files of data.")
     .longConf