This includes some changes to the scripts `README.md` to provide
some more information on the different Alacritty scripts.
A new script for testing the 24 bit support of Alacritty has been
added with the `24-bit-color.sh` name. This should help with
troubleshooting truecolor support issues.
Since `perf` is a standard tool which is available in the official
repositories for most distributions, it doesn't make much sense to
provide an installation script specifically for Ubuntu. As a result of
this, the script has been removed.
