DOCS-14073 add download link to landing page

Author: andf-mongodb

source/index.txt

@@ -65,6 +65,15 @@ Versioning
 
 .. include:: /includes/extracts/dbtools-version-all.rst
 
+Installation
+------------
+
+The {+dbtools+} can be downloaded from the `MongoDB Download Center
+<https://www.mongodb.com/try/download/database-tools?tck=docs_databasetools>`__.
+
+Please see the :doc:`installation guide for your platform
+</installation/installation>` for specific installation instructions.
+
 Additional Resources
 --------------------