[ci] Add automated Wiki publishing

Signed-off-by: Knut Ahlers <knut@ahlers.me>

.github/workflows/wiki-update.yml

@@ -0,0 +1,38 @@
+---
+
+name: wiki-update
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  wiki-update:
+    defaults:
+      run:
+        shell: bash
+
+    container:
+      image: luzifer/archlinux
+      env:
+        CGO_ENABLED: 0
+        GOPATH: /go
+
+    runs-on: ubuntu-latest
+
+    steps:
+
+      - name: Install required packages
+        run: |
+          pacman -Syy --noconfirm \
+            git
+
+      - uses: actions/checkout@v3
+
+      - name: Marking workdir safe
+        run: git config --global --add safe.directory /__w/twitch-bot/twitch-bot
+
+      - name: Update Wiki
+        run: 'git push https://github.com/Luzifer/twitch-bot.wiki.git $(git subtree split --prefix wiki HEAD):refs/heads/master --force'
+
+...