[SPARK-45963][SQL][DOCS] Restore documentation for DSv2 API

### What changes were proposed in this pull request?

This PR restores the DSv2 documentation. #38392 mistakenly added `org/apache/spark/sql/connect` as a private that includes `org/apache/spark/sql/connector`.

### Why are the changes needed?

For end users to read DSv2 documentation.

### Does this PR introduce _any_ user-facing change?

Yes, it restores the DSv2 API documentation that used to be there https://spark.apache.org/docs/3.3.0/api/scala/org/apache/spark/sql/connector/catalog/index.html

### How was this patch tested?

Manually tested via:

```
SKIP_PYTHONDOC=1 SKIP_RDOC=1 SKIP_SQLDOC=1 bundle exec jekyll build
```

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #43855 from HyukjinKwon/connector-docs.

Authored-by: Hyukjin Kwon <gurwls223@apache.org>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>

Author: HyukjinKwon

project/SparkBuild.scala

@@ -1361,7 +1361,7 @@ object Unidoc {
       .map(_.filterNot(_.getCanonicalPath.contains("org/apache/spark/util/io")))
       .map(_.filterNot(_.getCanonicalPath.contains("org/apache/spark/util/kvstore")))
       .map(_.filterNot(_.getCanonicalPath.contains("org/apache/spark/sql/catalyst")))
-      .map(_.filterNot(_.getCanonicalPath.contains("org/apache/spark/sql/connect")))
+      .map(_.filterNot(_.getCanonicalPath.contains("org/apache/spark/sql/connect/")))
       .map(_.filterNot(_.getCanonicalPath.contains("org/apache/spark/sql/execution")))
       .map(_.filterNot(_.getCanonicalPath.contains("org/apache/spark/sql/internal")))
       .map(_.filterNot(_.getCanonicalPath.contains("org/apache/spark/sql/hive")))

sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/SupportsMetadataColumns.java

@@ -58,8 +58,8 @@ public interface SupportsMetadataColumns extends Table {
    * Determines how this data source handles name conflicts between metadata and data columns.
    * <p>
    * If true, spark will automatically rename the metadata column to resolve the conflict. End users
-   * can reliably select metadata columns (renamed or not) with {@link Dataset.metadataColumn}, and
-   * internal code can use {@link MetadataAttributeWithLogicalName} to extract the logical name from
+   * can reliably select metadata columns (renamed or not) with {@code Dataset.metadataColumn}, and
+   * internal code can use {@code MetadataAttributeWithLogicalName} to extract the logical name from
    * a metadata attribute.
    * <p>
    * If false, the data column will hide the metadata column. It is recommended that Table

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

@@ -156,7 +156,7 @@ private[sql] object BucketTransform {
 }
 
 /**
- * This class represents a transform for [[ClusterBySpec]]. This is used to bundle
+ * This class represents a transform for `ClusterBySpec`. This is used to bundle
  * ClusterBySpec in CreateTable's partitioning transforms to pass it down to analyzer.
  */
 final case class ClusterByTransform(