Migrate docs to Vuepress

.github/workflows/ghpages.yml

@@ -1,24 +0,0 @@
-name: Build and deploy site to GitHub Pages
-on:
-  push:
-    paths:
-      - "docs/**"
-    branches:
-      - main
-jobs:
-  github-pages:
-    runs-on: ubuntu-16.04
-    steps:
-      - uses: actions/checkout@v2
-      - uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: 2.6
-      - uses: limjh16/jekyll-action-ts@v2
-        with:
-          enable_cache: true
-          jekyll_src: docs
-          gem_src: docs
-      - uses: peaceiris/actions-gh-pages@v3
-        with:
-          github_token: ${{ secrets.JEKYLL_PAT }}
-          publish_dir: ./_site