fix default path for qt-cmake for source build

Author: khanasif786

docs/en/qgc-dev-guide/getting_started/index.md

@@ -137,7 +137,7 @@ Example commands to build a default QGC and run it afterwards:
 1. Configure:
 
    ```sh
-	/Qt/6.8.2/gcc_64/bin/qt-cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Debug
+   ~/Qt/6.8.2/gcc_64/bin/qt-cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Debug
    ```
 
    Change the directory for qt-cmake to match your install location for Qt and the kit you want to use.