Creates the SDL_Renderer with the desired or default flags.
A full list of flags and info can be found in the SDL documentation about creating the renderer.
The normal SDL_CreateRenderer() can be used but to use it with LEXSDL it need to be set with LEXSDL_SetRenderer().
The SDL_Window must have been created or set. Check Management#window
If creation is succesfull a SDL_Renderer* is returned, there is no need to store it since it is stored internally and can be retrieved anytime with LEXSDL_GetRenderer().
SDL_Renderer* LEXSDL_CreateRenderer(uint32_t flags);