dx: github pull request vscode extension

Author: deckchairlabs

.devcontainer/devcontainer.json

@@ -10,6 +10,6 @@
     }
   },
   // This will install the vscode-deno extension
-  "extensions": ["denoland.vscode-deno"],
+  "extensions": ["denoland.vscode-deno", "GitHub.vscode-pull-request-github"],
   "remoteUser": "vscode"
 }