npm-{run, start, stop, restart, test}: add page

[Managor]

• The page(s) are in the correct platform directories: common, linux, osx, windows, sunos, android, etc.
• The page(s) have at most 8 examples.
• The page description(s) have links to documentation or a homepage.
• The page(s) follow the content guidelines.
• The page(s) follow the style guide.
• The PR title conforms to the recommended templates.
• Version of the command being documented (if known):

#14000

[Managor]

It felt a bit silly to create stub pages for the reserved keywords, but it was the best way I could think of to document them.