add the node version of markdownlint to the devcontainer

Author: dbarker

.devcontainer/Dockerfile.dev

@@ -20,9 +20,11 @@ COPY ci /opt/ci
 RUN apt update && apt install -y wget \
 	ninja-build \
 	libcurl4-openssl-dev \
-	markdownlint \
+	nodejs \
+	npm \
 	shellcheck
 
+RUN npm install -g markdownlint-cli
 RUN cd /opt/ci && bash setup_cmake.sh
 RUN cd /opt/ci && bash setup_ci_environment.sh
 RUN cd /opt && bash ci/setup_googletest.sh \

CONTRIBUTING.md

@@ -227,7 +227,7 @@ If you made changes to the Markdown documents (`*.md` files), install the latest
 [`markdownlint-cli`](https://github.com/igorshubovych/markdownlint-cli) and run:
 
 ```sh
-mdl <path to markdown file>.md
+markdownlint .
 ```
 
 If you modified shell scripts (`*.sh` files), install `shellcheck` and run: