Build the spec in the CI.

Author: sjrd

.github/workflows/spec.yml

@@ -0,0 +1,40 @@
+name: Specification
+
+on:
+  push:
+    tags:
+      - '*'
+    branches-ignore:
+      - 'gh-readonly-queue/**'
+  pull_request:
+  merge_group:
+  workflow_dispatch:
+
+env:
+  DOTTY_CI_RUN: true
+
+jobs:
+  specification:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./docs/_spec
+
+    steps:
+      - uses: actions/checkout@v3
+
+      # Keep in sync with ./docs/_spec/Dockerfile
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '2.7'
+      - name: Install required gems
+        run: |
+          gem update --system
+          gem install sass-embedded -v 1.58.0
+          gem install bundler:1.17.2 jekyll
+          bundle install
+          npm install bower
+
+      - name: Build the specification
+        run: |
+          bundle exec jekyll build

docs/_spec/Dockerfile

@@ -1,3 +1,5 @@
+# Keep in sync with relevant parts of .github/workflows/spec.yml
+
 FROM ruby:2.7
 
 RUN apt-get install -y curl \