npm-root: add page (#14581)

Co-authored-by: Wiktor Perskawiec <git@spageektti.cc>

pages/common/npm-root.md

@@ -0,0 +1,12 @@
+# npm root
+
+> Display path to `node_modules` directory.
+> More information: <https://docs.npmjs.com/cli/commands/npm-root>.
+
+- Display path to the local `node_modules` directory:
+
+`npm root`
+
+- Display path to the global `node_modules` directory:
+
+`npm root --global`