doc(readme): update gin link in README.md (#249)
doc(readme): update gin link in README.md (#249)

* Update gin link in README.md

* Use Gin instead of `gin` in documentation

The document generation currently fails when you have `gin` in the
title.  And "Gin" is the way it's branded in the docs:
https://gin-gonic.github.io/gin/

swaggo/swag