The project moved to meshcore-dev/meshcore, but two links still pointed at
ripplebiz/MeshCore: the GitHub Issues link in README and the git clone in the
FAQ build instructions.
Also fixes the FAQ build recipe:
- `pio run -e RAK_4631_Repeater` does not exist; the env is spelled
RAK_4631_repeater (variants/rak4631/platformio.ini:40).
- LORA_FREQ was given as 867.5; the default in [arduino_base] is 869.618
(platformio.ini:29). Reworded to point at the flag rather than a value that
drifts with the default preset.
- Renamed the venv so it no longer collides with the cloned directory name.
And one more env-name casing slip in the Raspberry Pi flashing instructions:
`Heltec_V3_companion_radio_ble` should be `Heltec_v3_...`. Release artifacts are
named directly from the env name (build.sh:147), and the two neighbouring
examples in the same block already use the lowercase spelling.