esphome-docs [sx127x] Add sx127x component

Description:

The SX127X component allows you to configure/control the SX1276, SX1277, SX1278 and SX1279 transceivers in ESPHome. Supported frequencies range from 137 MHz to 1020 MHz. Supported modulations include OOK, FSK, GFSK, MSK and GMSK. Support for both receive and transmit. These chips contain two modems. The LoRa modem is not supported by this component, only the FSK/OOK modem.

Datasheet: https://www.semtech.com/products/wireless-rf/lora-connect/sx1278#documentation

There are many devices in the market with an ESP32 already packaged with these radios, examples: https://www.lilygo.cc/en-ca/products/lora3 and https://shop.m5stack.com/products/m5stack-lora-module-433mhz-v1-1

There are already about a dozen or so people using my component. I currently use it for my 433 MHz AcuRite weather sensors (https://github.com/swoboda1337/acurite-esphome).

Generally I know others use 433 MHz for remotes, doorbells, garage doors, misc sensors etc. It would be nice to get these radios officially supported.

Related issue (if applicable): fixes

Pull request in esphome with YAML changes (if applicable): esphome/esphome#7490

Checklist:

[x] I am merging into next because this is new documentation that has a matching pull-request in esphome as linked above.
or
[ ] I am merging into current because this is a fix, change and/or adjustment in the current documentation and is not for a new component or feature.
[x] Link added in /index.rst when creating new documents for new components or cookbook.

Sep 24 '24 15:09 swoboda1337

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