How to test now that github-lightshow.herokuapp is gone?

[andreasabel]

The link to "Lightshow" doesn't lead anywhere anymore:

agda-github-syntax-highlighting/README.md

Line 8 in ba7aef4

- test your changes on [Lightshow](https://github-lightshow.herokuapp.com),

Apparently, this product has been shredded as of Sunday (1st May 2022):

• Sunsetting of Lightshow on 1 May 2022 github-linguist/linguist#5844