Add staticman to FlutterArsenal

[karx]

We looked at the options and finally decided to go with staticman as of now for adding comments to each project page.

I host and setup an self-hosted version of staticman, and share the endpoints here.
Something in the lines of https://api.flutterarsenal.com/staticman/{GITHUB USERNAME}/{GITHUB REPOSITORY}/{BRANCH}/{PROPERTY (optional)}

Looking forward to this.

[karx]

@VincentTam Thanks a ton for the help here.

Staticman v3 is now live on https://staticman.flutterarsenal.com
(Apologies for moving it to different endpoint. We are using api subdomain for github webhooks endpoint)
I am also merging your PR to move the staticman.yml file.

[karx]

@all-contributors please add @VincentTam for code.

[allcontributors]

@karx

I've put up a pull request to add @VincentTam! 🎉