Refactor update-symlinks script

[rjprins]

• Order functions to read top to bottom
• Use small helpers functions for readability
• Add some type hints

[wbolster]

thanks 🙏 this ancient py2 compatible code could use some 💕 indeed...

i spotted a few things; will have a closer look later:

• it crashes on this line in my symlinks.conf...

  .vim/ -> Vim/
  

  the problem seems to be the trailing slashes, and stripping those makes it work again. the slashes carry no meaning but serve as a ‘self-documenting’ note that this is about a directory. stripping them seems harmless.

• resulting symlinks now point absolute paths instead of relative paths.
  before:

  .bashrc -> Configuration/Bash/bashrc
  

  after:

  .bashrc -> /home/wbolster/Configuration/Bash/bashrc
  

  it does not matter much (both work), but i'm curious whether this was accidental or intentional?

• the type hints make this python3.6+ only. it may be a bit too new for some weird systems on which i use my dotfiles, e.g. synology ssh shells. i'll have to investigate further.

anyway, no action needed from you, these are mostly notes for myself 🙃

[rjprins]

I changed the script years ago, so don't really remember exactly what I changed. I think the absolute path vs relative path was to symlink /etc/ files as well. I wanted to run the script from a different directory than the symlinks.conf file? Something along those lines.