ci: add docs build to GHA

Signed-off-by: Henry Schreiner <[email protected]>

.github/workflows/docs.yml

@@ -0,0 +1,47 @@
+name: Docs
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  apidocs:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: mattnotmitt/doxygen-action@v1
+        with:
+          doxyfile-path: ./docs/Doxyfile
+
+      - uses: actions/upload-artifact@v3
+        with:
+          name: api-docs
+          path: html
+
+  gitbook:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 16
+
+      - name: Install requirements
+        run: |
+          npm install
+
+      - name: Build book
+        run: |
+          npx gitbook build . public
+          npx gitbook pdf . public/cli11.pdf
+
+      - uses: actions/upload-artifact@v3
+        with:
+          name: gitbook
+          path: public
+
+