Remove broken maitainability badge

Author: insolor

README.md

@@ -2,7 +2,6 @@
 
 [![Test](https://github.com/dfint/dfint64_patch/actions/workflows/test.yml/badge.svg)](https://github.com/dfint/dfint64_patch/actions/workflows/test.yml)
 [![Coverage Status](https://coveralls.io/repos/github/dfint/dfint64_patch/badge.svg)](https://coveralls.io/github/dfint/dfint64_patch)
-[![Maintainability](https://api.codeclimate.com/v1/badges/a9408116a0faae2cb117/maintainability)](https://codeclimate.com/github/dfint/dfint64_patch/maintainability)
 
 Text patcher for x64 bit version of the Dwarf Fortress game (work in progress).