New package: pie charts for SILE

[Omikhleia]

New 3rd-party package: piecharts.sile
Available on Luarocks

Some people will remember that it was part of an experiment I initiated in Summer 2022 with SILE 0.12.x, but never completed... But these re-vamped pie charts are much nicer!
It was very funny to code and hack -- I hope it will find some users.

[Omikhleia]

Of course, devoted communities go much farther in the same time scale, or less...

[alerque]

I've been meaning to port my personal finance reports (#plaintextaccounting via hledger of course) from LaTeX to SILE for years. I don't have any pretty charts just tables right now, but this might be the motivation I need to switch it over!