SWC syllabus episodes out of sync with material and not using site.curriculum variable

A couple of issues with the SWC syllabus:
- it is not using the site.curriculum variable to distinguish between Python inflammation and gapminder variants
- Python gapminder curriculum does not even exist in the syllabus page as an option
- Lesson module name and individual episode names are out of date/sync with the actual lesson (possibly the case with DC and LC syllabus too)
- Inconsistent style - in DC syllabus individual episodes are links where as in SWC syllabus episode names are not links but there is a 'Reference...' link at the end that links to the reference section of the lesson module (making it unclear for the learners where the actual episodes are).

I have seen a similar issue #648 and the RFC#4 discussion at https://github.com/carpentries/maintainer-RFCs/issues/4.

I propose that we simplify the syllabus pages to simply contain the name of the lessons with links to lesson pages and to scrap the individual lesson episode lists/links (but utilise the site.curriculum and site.flavour (for DC) variables as planned). This will reduce the size of the workshop page as well as simplify maintenance and reduce potential errors that are introduced when lessons change and syllabus gets out of sync. While it is nice to have individual lesson episodes listed - I am not sure they bring much benefit to participants especially if they are wrong. In my opinion, linking to the 'home' of the lesson website where all episodes are clearly listed is a much better way.

I understand that this will require a discussion by the maintainers team. I am happy to do a PR with the proposed changes.