tools: add make lint-md-clean

PR-URL: nodejs/node#12756
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

Makefile

@@ -948,6 +948,10 @@ bench: bench-net bench-http bench-fs bench-tls
 
 bench-ci: bench
 
+lint-md-clean:
+	$(RM) -r tools/remark-cli/node_modules
+	$(RM) -r tools/remark-preset-lint-node/node_modules
+
 lint-md-build:
 	if [ ! -d tools/remark-cli/node_modules ]; then \
 		cd tools/remark-cli && ../../$(NODE) ../../$(NPM) install; fi
@@ -1083,6 +1087,8 @@ endif
   lint-js-ci \
   list-gtests \
   lint-md \
+  lint-md-build \
+  lint-md-clean \
   pkg \
   release-only \
   run-ci \