Better comments around extensions/models

Added community pack data extensions for C# and Java.

Author: felickz

configs/default.yml

@@ -5,18 +5,21 @@ packs:
   - githubsecuritylab/codeql-cpp-queries
   # C#
   - githubsecuritylab/codeql-csharp-queries
-  - githubsecuritylab/codeql-csharp-extensions
-  - githubsecuritylab/codeql-csharp-library-sources
   # Go
   - githubsecuritylab/codeql-go-queries
   # Java
   - githubsecuritylab/codeql-java-queries
-  - githubsecuritylab/codeql-java-extensions
-  - githubsecuritylab/codeql-java-library-sources
   # JavaScript / Typescript
   - githubsecuritylab/codeql-javascript-queries
   # Python
   - githubsecuritylab/codeql-python-queries
   # Ruby
   - githubsecuritylab/codeql-ruby-queries
 
+  # Data extensions via Community Packs for libraries (library ext models are those generated by the corresponding queries in src) https://github.com/GitHubSecurityLab/CodeQL-Community-Packs
+  - githubsecuritylab/codeql-csharp-library-sources
+  - githubsecuritylab/codeql-java-library-sources
+
+  # Data extensions via Community Packs https://github.com/GitHubSecurityLab/CodeQL-Community-Packs
+  - githubsecuritylab/codeql-csharp-extensions
+  - githubsecuritylab/codeql-java-extensions