ruby: add change notes

Author: yoff

ruby/ql/src/change-notes/2025-04-02-adjust-uninitialized-local-alert-message.md

@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* The query `rb/uninitialized-local-variable` now take various guards into account and should produce fewer false positives. It also now comes with a help file.

ruby/ql/src/change-notes/2025-04-02-adjust-uninitialized-local-metadata.md

@@ -0,0 +1,4 @@
+---
+category: queryMetadata
+---
+* The query `rb/uninitialized-local-variable` now only produces alerts when it can find local flow; we have adjusted the precision to 'medium'.

ruby/ql/src/queries/variables/UninitializedLocal.ql

@@ -8,7 +8,7 @@
  * @tags quality
  *       reliability
  *       correctness
- * @precision high
+ * @precision medium
  */
 
 import codeql.ruby.AST