Add dependency script for Red Hat based distributions

[nixdaemon]

as the title says, this pr adds a very small script that Fedora users can run to install the needed dependencies to build the widget and fixes the readme to include Fedora

[nixdaemon]

Sorry for the constant edits(first time using github)I ended up writing a script for Red Hat based distributions instead of just Fedora, which should include RHEL and CentOS now as well. Feel free to check and merge if acceptable

[wsdfhjxc]

Thank you.