passing mmdc env on github actions.

Author: iancze

.github/workflows/gh_docs.yml

@@ -28,7 +28,7 @@ jobs:
       - name: Build the docs
         run: |
           make -C docs clean
-          make -C docs html
+          make -C docs html MERMAID_PATH="../node_modules/.bin/"
       - name: Deploy
         uses: peaceiris/actions-gh-pages@v3
         with:

docs/Makefile

@@ -29,7 +29,7 @@ ci-tutorials/%.ipynb: ci-tutorials/%.py ${CHARTS}
 
 # mermaid.js files
 _static/mmd/build/%.svg: _static/mmd/src/%.mmd
-	mmdc -i $^ -o $@
+	${MERMAID_PATH}mmdc -i $^ -o $@
 
 html: ${NOTEBOOKS} ${CHARTS}
 	python -m sphinx -T -E -b html -d _build/doctrees -D language=en . _build/html