docs: pull request template/lock and stale bot config/support bot config

.github/workflows/support.yml

@@ -0,0 +1,25 @@
+name: 'Support requests'
+
+on:
+  issues:
+    types: [labeled, unlabeled, reopened]
+
+jobs:
+  support:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: dessant/support-requests@v2
+        with:
+          github-token: ${{ github.token }}
+          support-label: 'support'
+          issue-comment: >
+            :wave: @{issue-author}, we use the issue tracker exclusively
+            for bug reports and feature requests. However, this issue appears
+            to be a support request. Please use our support channels
+            to get help with Overseerr.
+
+            - [Discord](https://discord.gg/PkCWJSeCk7)
+            - [GitHub Discussions](https://github.com/sct/overseerr/discussions)
+          close-issue: true
+          lock-issue: false
+          issue-lock-reason: 'off-topic'