gains render-readme action (#554)

.github/workflows/render-readme.yaml

@@ -0,0 +1,38 @@
+# Workflow derived from https://github.com/r-lib/actions/tree/v2/examples
+# Need help debugging build failures? Start at https://github.com/r-lib/actions#where-to-find-help
+on:
+  push:
+    paths: ['README.Rmd']
+
+name: render-readme
+
+jobs:
+  render-readme:
+    runs-on: macos-latest
+    env:
+      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: r-lib/actions/setup-pandoc@v2
+
+      - uses: r-lib/actions/setup-r@v2
+
+      - uses: r-lib/actions/setup-r-dependencies@v2
+
+      - name: Install the local package
+        run: |
+          Rscript -e 'install.packages("remotes")'
+          Rscript -e 'remotes::install_local(".")'
+
+      - name: Render README.Rmd file and Commit Results
+        run: |
+          README_PATH=($(git diff --name-only ${{ github.event.before }} ${{ github.sha }} | grep 'README.Rmd$'))
+          Rscript -e 'for (f in commandArgs(TRUE)) if (file.exists(f)) rmarkdown::render(f)' ${README_PATH[*]}
+          git config --local user.name "$GITHUB_ACTOR"
+          git config --local user.email "[email protected]"
+          git commit ${README_PATH[*]/.Rmd/.md} -m 'Re-build Rmarkdown files' || echo "No changes to commit"
+          git push origin || echo "No changes to commit"