DocsGHA: Grant write permission to pull-requests event

To enable the Documenter.jl preview comment URL in PRs, write permissions are required for the `pull_request` event in GHA. This change grants the necessary permissions. See related PR for the comment feature: TuringLang/actions#19.

Author: shravanngoswamii

.github/workflows/Docs.yml

@@ -15,7 +15,7 @@ concurrency:
 
 permissions:
   contents: write
-  pull-requests: read
+  pull-requests: write
 
 jobs:
   docs: