[Feature] Load docs in Pybricks Code as zip archive

[laurensvalk]

Is your feature request related to a problem? Please describe.
Pybricks Code takes quite a long time to fully load, or load new versions.

A lot of time is spent downloading a large amount of small files for the documentation.

Maybe this could be downloaded as a zipped archive and unpacked locally?

We can probably also avoid shipping the .txt files for the docs since the source is available on GitHub anyway.

[laurensvalk]

Some less impactful things we can do to reduce requests:

• Drop the .txt files. Since our sources are public and most info is in the .py files, we don't really need these.
• Embed the block .svg files in the html.

[laurensvalk]

This cuts the number of files in the docs html from 527 to 156, a reduction of 70%.

For the total Pybricks Code distribution, this is estimated at 371/852 = 43% reduction in the number of requests, which is nice.