Update package-managers.md

[TheBearodactyl]

Please Read

Link Submission

Please submit your link(s) to the Awesome Javascript repository (read first their contributing guide).

If they merge your pull request there, it will also be updated in this repository.

But if you really want to add it here, I would still review it.

Bug Fix or New Feature

For bug fixes or new features to this repository, delete this template text and proceed to provide information about the changes introduced in this pull request.

Contribution Agreement

By submitting a pull request to this repository, you are accepting this contribution agreement:

I dedicate any and all copyright interest in this software to the public domain. I make this dedication for the benefit of the public at large and to the detriment of my heirs and successors. I intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law.