feat: add symlink support

[boldandbrad]

Prerequisites

• I have read and understood the contributing guide.
• The commit message follows the conventional commits guidelines.
• Tests for the changes have been added (for bug fixes / features).
• Docs have been added/updated (for bug fixes / features).

I've built and tested within my own config using zsh on macOS.

Features

This PR closes #192.

• Add symlink support, because dotfiles!

Now you can:

# .aliae.yaml
...

link:
  - name: ~/.aliae.yaml
    target: ~/dotfiles/aliae.yaml
  - name: ~/.zshrc
    target: $DOTFILES/config/zsh/zshrc
  - name: ~/Brewfile
    value: /some/location/Brewfile
    if: eq .OS "darwin"

Outstanding issues/considerations

I've defaulted to using -f (force) by default since it would be annoying to get notifications at every shell invocation about symlinks already existing. There's probably a better solution where there is a force attribute on Links that defaults to false but can be overridden, or a global force-links config. In addition, cmd does not have a -f option for mklink, so additional work might need to be done to remove and replace the symlink if force is actually wanted. I'd like some help determining which approach makes most sense for this tool.

Let me know what you think!

[boldandbrad]

Rebased to main.

[JanDeDobbeleer]

@boldandbrad I will review later this week.

[boldandbrad]

@JanDeDobbeleer I don't remember the linter being upset before I rebased to main (and the only thing that changed in main to my knowledge was the one-line rendering order that was merged in #196).

It appears to be upset that I "duplicated" the test setup from the alias_test file to test the symlink functionality.

It also wants me to create a constant for the ln -sf ... cmd I used for most of the implementations.

For both of these "errors" I want to make sure I'm following the patterns of the codebase, any suggestions to resolve?

No rush at all, I know you've been busy chasing omp install issues. I haven't had much time in the last week to address this either, but still interested in feedback when you get a chance.

[JanDeDobbeleer]

Still in my list, I'll still try to look this week!

[JanDeDobbeleer]

This week turns out to be this week, I'll merge it in the coming days with some adjustments.

[JanDeDobbeleer]

I just need to test this and we're good to go

[JanDeDobbeleer]

@all-contributors please add @boldandbrad for doc

[allcontributors]

@JanDeDobbeleer

I've put up a pull request to add @boldandbrad! 🎉