docs: github pages deployment

Signed-off-by: Jan Larwig <jan@larwig.com>

Author: tuunit

.github/workflows/docs.yml

@@ -0,0 +1,71 @@
+name: Docs
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - .github/workflows/publish-docs.yml
+      - common.mk
+      - versions.mk
+      - docs/**
+      - hack/tools/**
+  pull_request:
+    paths:
+      - .github/workflows/publish-docs.yml
+      - common.mk
+      - versions.mk
+      - docs/**
+      - hack/tools/**
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: Build mdBook
+    runs-on: ubuntu-latest
+    steps:
+      - name: Clone the code
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        with:
+          persist-credentials: false
+
+      - name: Setup Go
+        uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
+        with:
+          go-version-file: go.mod
+
+      - name: Configure GitHub Pages
+        if: github.ref == 'refs/heads/main'
+        uses: actions/configure-pages@45bfe0192ca1faeb007ade9deae92b16b8254a0di # v6.0.0
+
+      - name: Build docs
+        run: make -C docs build
+
+      - name: Upload GitHub Pages artifact
+        if: github.ref == 'refs/heads/main'
+        uses: actions/upload-pages-artifact@fc324d3547104276b827a68afc52ff2a11cc49c9 # v5.0.0
+        with:
+          path: docs/book
+
+  publish:
+    name: Deploy docs to GitHub Pages
+    if: github.ref == 'refs/heads/main'
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      pages: write
+      id-token: write
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@cd2ce8fcbc39b97be8ca5fce6e763baed58fa128 # v5.0.0