Broken links in the resources documents

The following links on the Resources page are broken. They ought to be updated or removed.

Line 31 in 694ed3f

    
           [Dark energy is the biggest mystery in cosmology, but it may not exist at all](https://ec.europa.eu/research-and-innovation/en/horizon-magazine)<br>

acg/resources/README.md

Line 47 in 694ed3f

    
           [Astrophysicists, References and Websites](https://cosmologyscience.com/ref.htm)<br>

acg/resources/README.md

Line 55 in 694ed3f

    
           [Do We Have the Big Bang Theory All Wrong?](https://nautil.us/issue/15/turbulence/do-we-have-the-big-bang-theory-all-wrong)<br>

Line 31, the website has changed its structure. The link is now
https://ec.europa.eu/research-and-innovation/en/horizon-magazine/dark-energy-biggest-mystery-cosmology-it-may-not-exist-all-leading-physicist

Line 47, David Dilworth's website is down but the link should work when the site comes back on line. Can we leave the link as is? I guess not because GitHub will keep reporting it as an error... How about:
Astrophysicists, References and Websites, https://cosmologyscience.com/ref.htm

so the link is always there and GitHub doesn't complain. We would have to re-visit this later to enable the link when David's website is back online...

Line 55, the website has changed its structure, the link is now:
https://nautil.us/do-we-have-the-big-bang-theory-all-wrong-234989/

Could I have done these fix myself on your 'branch'?

We can leave dead links in the document, github does not care about that (I do 😄).

Edit the document and follow the steps in the HOWTO in order to commit the changes. Give it a try!?

Two links corrected, 3rd one left as is with a warning that the site is down.
What would you do about a dead link that is supposed to come back to life? Is there a ToDo list on GitHub I can use?