Website: Dead links to external themes

[MaKraMc]

I hope this is the right place for this as I could not find a repo for the Website. On the website there are two exernally linked themes with broken URLs.

1. https://raw.githubusercontent.com/MichaelGrznar/adminer-dark-css Should be: https://raw.githubusercontent.com/MichaelGrznar/adminer-dark-css/main/adminer-dark.css

2. https://raw.githubusercontent.com/pepa-linha/Adminer-Design-Dark/master/adminer.css Should be https://raw.githubusercontent.com/pepa-linha/Adminer-Design-Dark/master/adminer-dark.css See https://github.com/pepa-linha/Adminer-Design-Dark/pull/17