Add model pack publishing section to Rust docs

Add the 'Publish data extension files in a CodeQL model pack to share'
section, matching the structure used in C#, C++, Go, and Java docs.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: coadaflorin

docs/codeql/codeql-language-guides/customizing-library-models-for-rust.rst

@@ -45,6 +45,11 @@ Each YAML file may contain one or more top-level extensions.
 
 Data extensions use union semantics, which means that the tuples of all extensions for a single extensible predicate are combined, duplicates are removed, and all of the remaining tuples are queryable by referencing the extensible predicate.
 
+Publish data extension files in a CodeQL model pack to share
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You can group one or more data extension files into a CodeQL model pack and publish it to the GitHub Container Registry. This makes it easy for anyone to download the model pack and use it to extend their analysis. For more information, see `Creating a CodeQL model pack <https://docs.github.com/en/code-security/codeql-cli/using-the-advanced-functionality-of-the-codeql-cli/creating-and-working-with-codeql-packs#creating-a-codeql-model-pack>`__ and `Publishing and using CodeQL packs <https://docs.github.com/en/code-security/codeql-cli/using-the-advanced-functionality-of-the-codeql-cli/publishing-and-using-codeql-packs/>`__ in the CodeQL CLI documentation.
+
 Extensible predicates used to create custom models in Rust
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~