docs: add Ballista link to landing page (#17746) (#17775)

* docs: add Ballista link to landing page (#17746)

This adds a link and description for DataFusion Ballista to the landing page, as suggested in issue #17746. Ballista is a distributed compute platform built on top of DataFusion.

Closes: #17746

* fix(docs): update Ballista link

* updated theory part

Author: Nihallllll

docs/source/index.rst

@@ -51,12 +51,14 @@ The following related subprojects target end users and have separate documentati
   queries.
 - `DataFusion Comet <https://datafusion.apache.org/comet/>`_ is an accelerator for Apache Spark based on
   DataFusion.
+- `DataFusion Ballista <https://datafusion.apache.org/ballista/>`_ is distributed processing extension for DataFusion.
 
 "Out of the box," DataFusion offers `SQL <https://datafusion.apache.org/user-guide/sql/index.html>`_
 and `Dataframe <https://docs.rs/datafusion/latest/datafusion/dataframe/struct.DataFrame.html>`_ APIs,
 excellent `performance <https://benchmark.clickhouse.com/>`_, built-in support for CSV, Parquet, JSON, and Avro,
 extensive customization, and a great community.
 `Python Bindings <https://github.com/apache/datafusion-python>`_ are also available.
+`Ballista <https://datafusion.apache.org/ballista/>`_ is Apache DataFusion extension enabling the parallelized execution of workloads across multiple nodes in a distributed environment.
 
 DataFusion features a full query planner, a columnar, streaming, multi-threaded,
 vectorized execution engine, and partitioned data sources. You can
@@ -163,6 +165,6 @@ To get started, see
    :maxdepth: 1
    :caption: DataFusion Subprojects
 
-   DataFusion Ballista <https://arrow.apache.org/ballista/>
+   DataFusion Ballista <https://datafusion.apache.org/ballista/>
    DataFusion Comet <https://datafusion.apache.org/comet/>
    DataFusion Python <https://datafusion.apache.org/python/>