Add gitment w/ npm auto-update via single pacakge.json

[sashberd]

Pull request for issue: #12420

Checklist for Pull request or lib adding request issue follows the conventions.

Note that if you are using a distribution purpose repository/package, please also provide the url and other related info like popularity of the source code repo/package.

Profile of the lib

• Git repository (required):https://github.com/imsun/gitment
• Official website (optional, not the repository):https://imsun.github.io/gitment/
• NPM package url (optional):https://www.npmjs.com/package/gitment
• License and its reference:MIT
• GitHub / Bitbucket popularity (required):
  • Count of watchers:62
  • Count of stars:3.7k
  • Count of forks:352
• NPM download stats (optional):
  • Downloads in the last day:
  • Downloads in the last week:184
  • Downloads in the last month:

Essential checklist

• I'm the author of this library
  • I would like to add link to the page of this library on CDNJS on website / readme
• This lib was not found on cdnjs repo
• No already exist / duplicated issue and PR
• The lib has notable popularity
  • More than 200 [Stars / Watchers / Forks] on [GitHub / Bitbucket]
  • More than 800 downloads stats per month on npm registry
• Project has public repository on famous online hosting platform (or been hosted on npm)

Auto-update checklist

• Has valid tags for each versions (for git auto-update)
• Auto-update setup
• Auto-update target/source is valid.
• Auto-update filemap is correct.

Git commit checklist

• The first line of commit message is less then 50 chars, be clean and clear, easy to understand.
• The parent of the commit(s) in the PR is not old than 3 days.
• Pull request is sending from a non-master branch with meaningful name.
• Separate unrelated changes into different commits.
• Use rebase to squash/fixup dummy/unnecessary commits into only one commit.
• Close corresponding issue in commit message
• Mention related issue(s), people in commit message, comment.

[MattIPv4]

Lgtm.