Updated module to Unicode 15.1

[gaspardpetit]

Hello,

I am providing an update to this module for Unicode 15.1; In addition, there are several improvements:

• This change improves performance of the lookup function by about 300x.; on my PC, running the following:

    start_time = time.time()
    for i in range(0, 65535):
        which_scripts(chr(i))
    end_time = time.time()

Goes from ~3100ms to ~10ms

Some other fixes are also provided for style (pylint), allowing the project to pass pylint.
I have also added unittests to the project, and added github actions to test:

• the new unittests
• the documentation in module
• the readme

I have cleaned and updated the update scripts, and ran them against the Unicode 15.1 files.

As a bonus, I've also added a couple of badges in the README (you will want to point them to your own github actions once merged)

I understand that this project has not been updated in several years, if you are no longer maintaining it, would you mind giving me ownership so I can update PyPI with an updated version?

[gaspardpetit]

• I also added a get_scripts to get the scripts in a text (rather than in a chr
• I have also pinned the version of the module to the version of Unicode. If this module was to be released to PyPI, it would be released as 15.1.0