Auto-deploy/publish to gh-pages w/ GitHub Actions (#466)

This is based on the setup Domenic Denicola put together at
https://gist.github.com/domenic/ec8b0fc8ab45f39403dd

.github/workflows/build.yml

@@ -0,0 +1,22 @@
+name: Build
+on:
+  pull_request:
+    branches:
+    - main
+  push:
+    branches:
+    - main
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build
+      run: make ci
+    - name: Deploy
+      if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
+      uses: peaceiris/actions-gh-pages@v3
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        publish_dir: ./out

.gitignore

@@ -0,0 +1 @@
+out/

Makefile

@@ -1,3 +1,5 @@
+SHELL=/bin/bash
+
 all: index.html ./api/index.html ./cookies/index.html ./pinning/index.html
 
 force:
@@ -26,3 +28,22 @@ pinning/index.html: pinning/index.src.html
 
 publish:
 	git push origin master
+
+ci: out/index.html
+
+out/index.html: index.src.html
+	mkdir -p out
+	@ (HTTP_STATUS=$$(curl https://api.csswg.org/bikeshed/ \
+	                       --output $@ \
+	                       --write-out "%{http_code}" \
+	                       --header "Accept: text/plain, text/html" \
+	                       -F die-on=nothing \
+	                       -F file=@$<) && \
+	[[ "$$HTTP_STATUS" -eq "200" ]]) || ( \
+		echo ""; cat $@; echo ""; \
+		$(RM) -r out; \
+		exit 22 \
+	);
+
+clean:
+	$(RM) -r out