docs: Numerous spelling and grammer fixes in flight controller section (#26582)

docs/en/flight_controller/pixhawk3_pro.md

@@ -1,6 +1,6 @@
 # Pixhawk 3 Pro (Discontinued)
 
-:::warning
+::: warning
 PX4 does not manufacture this (or any) autopilot.
 Contact the [manufacturer](https://store-drotek.com/) for hardware support or compliance issues.
 :::
@@ -14,7 +14,7 @@ The board was designed by [Drotek<sup>&reg;</sup>](https://drotek.com) and PX4.
 The main hardware documentation is here: https://drotek.gitbook.io/pixhawk-3-pro/hardware
 :::
 
-:::tip
+::: tip
 This autopilot is [supported](../flight_controller/autopilot_pixhawk_standard.md) by the PX4 maintenance and test teams.
 :::
 
@@ -40,14 +40,14 @@ No longer available.
 
 ## Building Firmware
 
-:::tip
+::: tip
 Most users will not need to build this firmware!
 It is pre-built and automatically installed by _QGroundControl_ when appropriate hardware is connected.
 :::
 
 To [build PX4](../dev_setup/building_px4.md) for this target:
 
-```
+```sh
 make px4_fmu-v4pro_default
 ```