Setup deploy via GitHub action

.github/workflows/deploy.yml

@@ -0,0 +1,46 @@
+name: Deploy
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.7
+
+      - name: Set up Bundler
+        run: |
+          gem install bundler
+          bundle config path vendor/bundle
+
+      - name: Cache Ruby dependencies
+        uses: actions/cache@v2
+        with:
+          path: vendor/bundle
+          key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-gems-
+
+      - name: Install dependencies
+        run: |
+          bundle install --without development
+
+      - name: Build
+        run: |
+          ./script/build
+
+      - name: Deploy to GitHub Pages
+        uses: JamesIves/github-pages-deploy-action@releases/v3
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          BRANCH: gh-pages
+          FOLDER: build

.gitignore

@@ -1,3 +1,5 @@
 vendor
 .DS_Store
 .bundle
+/build/*
+!/build/.gitkeep

README.md

@@ -25,10 +25,10 @@ Most people fork and edit these to suit, but if you find an issue or make an imp
 4. To compile the agreements into HTML:
 
    ```
-   $ bundle exec ./compile
+   $ ./script/compile
    ```
 
-You should find some HTML in the build directory. This tool is a bit rough & ready, and we probably won't spend much time improving it, but do raise an issue if it just doens't work at all.
+You should find some HTML in the build directory.
 
 ## Modification