npm-check: add page (#2107)

pages/common/npm-check.md

@@ -0,0 +1,19 @@
+# npm-check
+
+> Check for outdated, incorrect, and unused npm package dependencies.
+
+- Display a report of outdated, incorrect, and unused dependencies:
+
+`npm-check`
+
+- Interactively update out-of-date packages:
+
+`npm-check --update`
+
+- Update everything without prompting:
+
+`npm-check --update-all`
+
+- Don't check for unused packages:
+
+`npm-check --skip-unused`