Update mavlink docs since INAV 8.0.0 is now officially released (#448)

* Update mavlink.md since INAV 8.0.0 is now officially released

Remove information about pre-release and older inav versions.

Add LQ/RSSI format options for OSD.

* Update mavlink.md

Changes suggested by Senk0.

* Update mavlink.md

docs/software/mavlink.md

@@ -81,15 +81,13 @@ The minimum versions to use this feature are:
     1. Configure MAVLink sending rate with MAV_0_RATE to `9600 B/s`
 
 === "INAV"
-    **UNSUPPORTED, CURRENTLY IN DEVELOPMENT** -
-    Released versions (up to version 7) of iNav cannot use MAVLink due the limitations highlighted in the Betaflight tab.
-    As of version 8.0, which is currently not released yet, these limitations have been partially resolved and there is limited MAVLink support.
+    Released versions of INAV (from version 8 onwards) can use MAVLink for flight monitoring. However, given that INAV is primarily an MSP flight controller, full functionality and configuration via MAVLink should not be expected.
 
-    For testing of development version:
     For the below steps, when a UART connection is mentioned, it will be written as `UARTx`. Replace `x` with the UART number you are using.
 
     1. In the Ports tab, set the UARTx `Telemetry Protocol` to `MAVLink`, and the baud rate to `460800`. Make sure `RX Serial` is disabled.
     1. In the Receiver tab, set the Receiver type to `SERIAL` and the `Serial Receiver Provider` to `MAVLink`. Leave inverted & half-duplex `disabled`.
+    1. In the CLI, enter ```set mavlink_radio_type=ELRS``` to get the correct RSSI and LQ values on INAV's OSD.
 
 === "Betaflight"