feat: add xl9535 support, issue #400

[mahnunchik]

I was able to add support for XL9535 chip and relay board I want to use.

Notes

• There is currently no working python package for this chip, but the implementation is extremely simple.
• The implementation is only supports output mode. Input mode can be added later if devices appear.
• Add support for XL9535 relay board #400
• Datasheet https://www.lcsc.com/datasheet/lcsc_datasheet_2211110930_XINLUDA-XL9535_C561273.pdf
• ESPHome integration https://github.com/esphome/esphome/tree/857a3dcf72d74fa53fba2f6c63f2ceaaec3e5e59/esphome/components/xl9535
• Python module and description https://github.com/mcauser/micropython-xl9535-kxv5-relay
• NodeJS module https://github.com/isky04/node-red-contrib-xl9535

[mahnunchik]

@flyte @mschlenstedt @BenjiU may I ask for the review?

[BenjiU]

Top, but would be nice to mention the new module in the Readme in the "GPIO Modules" section

[mahnunchik]

@BenjiU I've updated README manually in this PR because I've faced with a lot of changes when generate it from the template #405