Add github actions for docgen (#7)

* Create main.yml
* Update CONTRIBUTING and REAMDE.
Explain that Github Actions generate README.

1 files changed, 34 insertions, 0 deletions

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 00000000..f7f01349
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,34 @@
+name: CI
+
+on: [push]
+
+jobs:
+  docgen:
+    runs-on: [ubuntu-latest]
+    if: github.ref != 'master'
+    steps:
+    - uses: actions/checkout@v1
+    - run: date +%F > todays-date
+    - name: Restore cache for today's nightly.
+      uses: actions/cache@v1.0.0
+      with:
+        path: _neovim
+        key: ${{ runner.os }}-nightly-${{ hashFiles('todays-date') }}
+    - name: Setup from neovim nightly and run docgen
+      run: |
+        curl -OL https://raw.githubusercontent.com/norcalli/bot-ci/master/scripts/github-actions-setup.sh
+        source github-actions-setup.sh nightly-x64
+        nvim -u NONE +'set rtp+=$PWD' +"luafile scripts/docgen.lua" +q
+    - name: Commit changes
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        COMMIT_MSG: |
+          [docgen] Update README.md
+          skip-checks: true
+      run: |
+        git config user.email "actions@github"
+        git config user.name "Github Actions"
+        git remote set-url origin https://x-access-token:${GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git
+        git add README.md
+        # Only commit and push if we have changes
+        git diff --quiet && git diff --staged --quiet || (git commit -m "${COMMIT_MSG}"; git push origin HEAD:${GITHUB_REF})