Fix broken link [skip ci]
## Overview
* How to install it
- * [Installation on Linux](https://github.com/Bios-Marcel/cordless#installation-on-linux)
+ * [Installing on Linux](https://github.com/Bios-Marcel/cordless#installing-on-linux)
* [Using pre-built binaries](https://github.com/Bios-Marcel/cordless#using-pre-built-binaries)
* [Building it from source](https://github.com/Bios-Marcel/cordless#building-it-from-source)
* [Login](https://github.com/Bios-Marcel/cordless#login)
