📦 Add link check action

[TechWiz-3]

In this PR, I have added a workflow which checks links and fails if any of them are broken.

Disclaimer: this action is my own action, the repo is here

You can view the logs of the workflow on my fork here. 9 links were found to be broken. Please note because of the amount of links, the workflow took 30 minutes.

Also, you may note a little bug in the logs --> Link validity unkwown with 402 Forbidden return code 403 - this bug has been fixed.

Let me know if you'd like me to change anything, any feedback is appreciated either way :)

[krzjoa]

Thank you for this contribution, it'll help a lot 😎

[TechWiz-3]

Thanks you, glad it'll help ☺️

Just some helpful notes:

• since submitting this PR I created a 'fast' version. If you'd like the workflow to be much faster (a few minutes maximum) check it out. It just requires a GitHub token used to make requests to the github api without getting rate limited.
• if you wish the workflow to run regardless of pushes you can add

  on:
    schedule:
      - cron: '0 1 * * *'  # 1 am everyday
    push: