Fix typo in macOS compiling (#3801)

development/compiling/compiling_for_osx.rst

@@ -66,7 +66,7 @@ editor binary built with ``target=release_debug``::
     cp bin/godot.osx.opt.tools.universal Godot.app/Contents/MacOS/Godot
     chmod +x Godot.app/Contents/MacOS/Godot
 
-If you are building the ``master`` branch, additionally copy the Vulkan library:
+If you are building the ``master`` branch, additionally copy the Vulkan library::
 
     mkdir -p Godot.app/Contents/Frameworks
     cp <Vulkan SDK path>/macOS/libs/libMoltenVK.dylib Godot.app/Contents/Frameworks/libMoltenVK.dylib