fix: homogenize authoring format and place (#7034)

* fix: homogenize authors format and place

- use colon as author separator (replaces `&`, `and`, `y`, `e`, `et`...)
- ensures is placed after resource title, not part of itself `title - author`
- `et al.` as special author/token to group many

* remove double comma

* fix: recover traducer role notations as `trad.:`

* detect and apply some `trad.:`s role anotation

* chore: `trad.:` to `trl.:`

Apply suggestion made by Eric at https://github.com/EbookFoundation/free-programming-books/pull/7034#discussion_r954014539

Co-authored-by: Eric Hellman <eric@hellman.net>

* Sort author - format

* fix: remove empty authors (dash is alone)

Used regex: `-\s+(\(|$)`

* format: change to `edt.:` role

Definition list at https://www.loc.gov/marc/relators/relaterm.html

Co-authored-by: Eric Hellman <eric@hellman.net>

more/free-programming-interactive-tutorials-en.md

@@ -172,7 +172,7 @@
 * [HTML Tutorial](https://www.scaler.com/topics/html/) - Scaler Topics
 * [Knights of the Flexbox Table](https://knightsoftheflexboxtable.com)
 * [Learn by doing beginner projects](https://dash.generalassemb.ly)
-* [Learn CSS: an evergreen CSS course and reference to level up your styling expertise](https://web.dev/learn/css/) - Andy Bell, Rachel Andrew, Una Kravets, Adam Argyle, Rob Dodson, Jiwoong Lee et al. (web.dev)
+* [Learn CSS: an evergreen CSS course and reference to level up your styling expertise](https://web.dev/learn/css/) - Andy Bell, Rachel Andrew, Una Kravets, Adam Argyle, Rob Dodson, Jiwoong Lee, et al. (web.dev)
 * [Learn HTML & CSS interactively](https://www.codecademy.com/learn/web)
 * [Prototyping a professional website](https://www.codecademy.com/learn/make-a-website)
 * [Responsive Web Design Certification](https://www.freecodecamp.org/learn/responsive-web-design/) - freeCodeCamp