Githawk: Added url scheme to open GitHawk app

[RishabhTayal]

It will be nice to have a url scheme for the app

Bug Report Dump (Auto-generated)

Version 1.16.0 (1513134612)
Device: iPhone X (iOS 11.2)
TestFlight: false

[unnamedd]

An existing issue was opened before, you can check it here #418

[BasThomas]

Thanks for following up, @unnamedd!

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