[crux-contrib] Some more ports for contrib(?)

Hey everybody! After maintaining some ports in contrib for a while, I rechecked my repo and found some ports that might be beneficial to have in contrib. mksh - It already was in Contrib a while ago, afaik. sxhkd - There's no xbindkeys available in the official repos or contrib and this seems to be a more lightweight solution xsel - xclipboard alternative crawl - A great and widely spread roguelike. crawl-tiles - Tiles version. You can find all these ports in my personal repo at: https://github.com/Doomicide/crux-ports Let me know what you think. Sincerely, Maximilian D.