Rust: Add missing link (to existing doc).

Author: geoffw0

docs/codeql/writing-codeql-queries/creating-path-queries.rst

@@ -33,6 +33,7 @@ For more language-specific information on analyzing data flow, see:
 - ":ref:`Analyzing data flow in JavaScript/TypeScript <analyzing-data-flow-in-javascript-and-typescript>`"
 - ":ref:`Analyzing data flow in Python <analyzing-data-flow-in-python>`"
 - ":ref:`Analyzing data flow in Ruby <analyzing-data-flow-in-ruby>`"
+- ":ref:`Analyzing data flow in Rust <analyzing-data-flow-in-rust>`"
 - ":ref:`Analyzing data flow in Swift <analyzing-data-flow-in-swift>`"
 
 Path query examples