ci: remove gatsby workflow

.github/workflows/gatsby.yml

@@ -1,37 +0,0 @@
-name: Gatsby GH Pages
-
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
-
-jobs:
-  deploy:
-    runs-on: ubuntu-18.04
-    steps:
-      - uses: actions/checkout@v2
-
-      - name: Setup Node
-        uses: actions/setup-node@v2.1.2
-        with:
-          node-version: '12.x'
-
-      - name: Cache dependencies
-        uses: actions/cache@v2
-        with:
-          path: ~/.npm
-          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
-          restore-keys: |
-            ${{ runner.os }}-node-
-
-      - run: cd docs && npm ci && npm run format && npm run test && npm run build
-
-      - name: Deploy
-        uses: peaceiris/actions-gh-pages@v3
-        with:
-          personal_token: ${{ secrets.ACCESS_TOKEN }}
-          cname: discordeno.js.org
-          user_name: 'github-actions[bot]'
-          user_email: 'github-actions[bot]@users.noreply.github.com'
-          publish_dir: ./docs/public