Mention Go in codeql-for-go toctree

Author: egregius313

docs/codeql/codeql-language-guides/codeql-for-go.rst

@@ -12,6 +12,7 @@ Experiment and learn how to write effective and efficient queries for CodeQL dat
    codeql-library-for-go
    abstract-syntax-tree-classes-for-working-with-go-programs
    modeling-data-flow-in-go-libraries
+   customizing-library-models-for-go
 
 -  :doc:`Basic query for Go code <basic-query-for-go-code>`: Learn to write and run a simple CodeQL query.
 
@@ -21,3 +22,5 @@ Experiment and learn how to write effective and efficient queries for CodeQL dat
 
 -  :doc:`Modeling data flow in Go libraries <modeling-data-flow-in-go-libraries>`: When analyzing a Go program, CodeQL does not examine the source code for external packages. 
    To track the flow of untrusted data through a library, you can create a model of the library.
+
+-  :doc:`Customizing library models for Go <customizing-library-models-for-go>`: You can model frameworks and libraries that your codebase depends on using data extensions and publish them as CodeQL model packs.