npm-ls: add page (#14769)

* npm-ls: add page

* Improve wording

* Add alias page

* Fix typo

* Fix styling of description

---------

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>
Co-authored-by: Wiktor Perskawiec <git@spageektti.cc>

pages/common/npm-list.md

@@ -0,0 +1,7 @@
+# npm list
+
+> This command is an alias of `npm ls`.
+
+- View documentation for the original command:
+
+`tldr npm ls`