refactor: replace KaTeX with MathML, temml and Fira Math font

[elbotho]

Experiment. Demo: https://frontend-git-katex-to-mathml-serlo.vercel.app/community/298700/lerne-latex Current version: http://serlo.org/community/298700/lerne-latex

I would like to test this on serlo.org staging, ~but it needs a way import styles before releasing in the editor~

I just realized that MathML support is very good now across the main browsers.

Upsides:

• very pretty sans serif font
• less markup
• less traffic
• probably better performance
• better for SEO
• less custom stuff
• mhchem should also work
• a bit less bundle size (but still no lightweight)

Potential downsides:

• unknown how compatible our LaTeX code is (but coverage should be good)
• newer solution, less established
• …?

Unfortuately copy/pasting from/to other software does not work in both approaches.

Todo: Test, discuss, ~add macros again~.

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📦 Next.js Bundle Analysis for @serlo/frontend

This analysis was generated by the Next.js Bundle Analysis action. 🤖

🎉 Global Bundle Size Decreased

Page	Size (compressed)
global	104.71 KB (🟢 -827 B)

Details

The global bundle is the javascript bundle that loads alongside every page. It is in its own category because its impact is much higher - an increase to its size means that every page on your website loads slower, and a decrease means every page loads faster.

Any third party scripts you have added directly to your app using the <script> tag are not accounted for in this analysis

If you want further insight into what is behind the changes, give @next/bundle-analyzer a try!

Twenty-five Pages Changed Size

The following pages changed size from the code in this PR compared to its base branch:

Page	Size (compressed)	First Load
/[...slug]	107.67 KB (-7 B)	212.38 KB
/___bot_or_not	114.88 KB (-7 B)	219.59 KB
/___editor_preview	88.89 KB (🟢 -17 B)	193.6 KB
/___old_comments	97.25 KB (-9 B)	201.96 KB
/biologie	175.62 KB (-7 B)	280.34 KB
/chemie	175.62 KB (-7 B)	280.33 KB
/content-only/[...slug]	96.54 KB (-7 B)	201.26 KB
/discussions	93.79 KB (-9 B)	198.5 KB
/entity/create/[type]/[taxonomyId]	160.23 KB (-16 B)	264.95 KB
/entity/repository/add-revision/[...id]	159.89 KB (-16 B)	264.61 KB
/entity/repository/compare/[entity_id]/[revision_id]	111.45 KB (-7 B)	216.17 KB
/event/history	124.46 KB (-9 B)	229.17 KB
/event/history/[...slug]	125.44 KB (-9 B)	230.15 KB
/event/history/user/profile/[username]	127.82 KB (-9 B)	232.54 KB
/gleichungs-app	162.07 KB (-13 B)	266.79 KB
/informatik	175.63 KB (-7 B)	280.34 KB
/lerntipps	175.62 KB (-7 B)	280.33 KB
/license/detail/[id]	82.88 KB (-7 B)	187.59 KB
/mathe	175.62 KB (-7 B)	280.33 KB
/nachhaltigkeit	175.63 KB (-7 B)	280.34 KB
/page/create	159.9 KB (-16 B)	264.62 KB
/taxonomy/term/create/[parent_id]/[id]	159.61 KB (-16 B)	264.32 KB
/user/notifications	126.69 KB (-9 B)	231.41 KB
/user/profile/[username]	194.28 KB (-16 B)	299 KB
/user/settings	136.93 KB (🟢 -16 B)	241.64 KB

Details

Only the gzipped size is provided here based on an expert tip.

First Load is the size of the global bundle plus the bundle for the individual page. If a user were to show up to your website and land on a given page, the first load size represents the amount of javascript that user would need to download. If next/link is used, subsequent page loads would only need to download that page's bundle (the number in the "Size" column), since the global bundle has already been downloaded.

Any third party scripts you have added directly to your app using the <script> tag are not accounted for in this analysis

Next to the size is how much the size has increased or decreased compared with the base branch of this PR. If this percentage has increased by 20% or more, there will be a red status indicator applied, indicating that special attention should be given to this.

[LarsTheGlidingSquirrel]

For using this in the editor npm package, I think we need a way to apply the styling there. Do you have any preferences how to do this?

[elbotho]

@LarsTheGlidingSquirrel sorry for moving the tailwind files in here, that makes the PR a lot less readable than it could be.

I did some more test and it looks find for serlo.org content so far. A bit smaller / compact in some places, but nothing obviously wrong I could find. Will merge to staging for testing and make a new editor version.