Script to download and install binary language files for spell checker

[blipk]

This script downloads and installs the binary dictionary files that ungoogled chromium uses for its spell checking feature.

It will look for both OS install and Flatpak install config directories and installs to both/either of them if they exist.

A custom install directory can also be specified.

Currently only works on Linux.

Adapted from the instructions in the FAQ here:
https://ungoogled-software.github.io/ungoogled-chromium-wiki/faq#how-do-i-fix-the-spell-checker

This PR is based on the recommendation here:
ungoogled-software/ungoogled-chromium#188 (comment)

[PF4Public]

Brief description and usage examples are in the top of the script, looks good. @networkException do you have any comments?

[networkException]

Well I would not try to parse Gitiles' HTML but rather just access the repository using git but otherwise looks good

[blipk]

@networkException

I looked at using gitpython but it complicates the script a lot more, have to (shallow) clone the repo, set up temporary directories etc

It is also a lot slower.

requests and beautifulsoup are generally more available than gitpython as well: https://piptrends.com/compare/gitpython-vs-beautifulsoup4-vs-requests

[blipk]

There was also some discussion here about just including the dictionary files (or downloading and generating them in your build process): ungoogled-software/ungoogled-chromium#188

Searching my home directory it seems other GPL/MIT/Apache licenced software includes the binary .bdic files without problem e.g. VSCodium, drawio, heroic launcher etc

[PF4Public]

binary .bdic

Remember, we have a script to specifically prune all binaries :))