Documentation tweak

Author: slouken

docs/README-main-functions.md

@@ -208,9 +208,9 @@ it's useful to know if this was a successful or failing run of the app.
 
 ## Using main functions from other languages
 
-If not working in C/C++, using SDL's entry points is still possible but more
-complex. Please refer to https://wiki.libsdl.org/SDL3/NonstandardStartup for
-the technical details.
+If you're not using C/C++, using SDL's entry points is still possible but is
+more complex. Please refer to https://wiki.libsdl.org/SDL3/NonstandardStartup
+for the technical details.
 
 
 ## Summary and Best Practices