CI: add a github action to check dead links

[olivierodo]

Hello @yosriady , I came across your AMAZING repo and after clicking in a few links I came through a few invalid links... Then allow me to propose a Github action that would be able to detect the if a link is dead or not 😅.

The Github action used is https://github.com/marketplace/actions/404-links

When I run the Action on my fork here is the result: https://github.com/olivierodo/awesome-api-devtools/actions/runs/4024361441

Preview

Let me know if you have any question.

[olivierodo]

So far the remaining work on this PR is:

• A few links that need to be remove,
• Swagger.io needs to be added to the whitelist.

If you are interested by this Github action integration, just let me know then I will finalize the PR.

[yosriady]

@olivierodo Thanks for this contribution. Please go ahead with the changes and we can merge it!