Major work is needed on the tutorial: should we go with PRs or a new branch?

[harabat]

Hey, I'm going to do some major work on the tutorial-extensions repo, should I advance PR by PR, or would it make more sense to create a new branch (like you did for switching to Django v3.1 on the main tutorial?)

Here are some of the things I want to change (let me preface this by saying that the tutorial's great):

1. Better organise the whole thing

   • Move all translations under a "Other languages" dropdown instead of having them as chapters on the same level as the main version
   • Make the language of each tutorial clear, as two of them are just called "Django Girls: Tutorial extensions"

2. Re-organise the en tutorial

   • The en chapter's sub-chapters are a mess, the actual order of sub-chapters is random (the sub-chapter "Summary" is in the middle of the chapter, the README itself is second-to-last, so people need to constantly go back to README instead of advancing to the "Next" sub-chapter)
   • Titles are not representative of the content ("Domain", "Add more")

3. Move to Bootstrap v5

   • The tutorial works with Bootstrap v3 and makes heavy use of glyphicons, which are not included in Boostrap since v4, but can be easily replaced with Bootstrap Icons

4. Change some content:

   • The code in the tutorial does not produce the polished screenshots in the tutorial
   • Redirect people to https://www.postgresql.org/download/ for the most up-to-date and complete overview of the PostgreSQL installation process, which seems to be a pain point given the number of Issues in this repo
   • Typos and grammar