Rename and simplify renderer functions, add FPS control, and add keyboard constants.
init_win_cli() -> init_renderer(), clear_con() -> clear_console(), swap_buffers(float) -> swap_buffers() and a new set_fps(float) were introduced.
init_renderer() now sets a default fps of 60.
main.c updated to use the new renderer API (init_renderer, clear_console, swap_buffers) and removed the old cursor positioning usage.
Also added KEY_A..KEY_Z defines to src/input/win_input.h for letter key codes.
Will add a camera system and a status bar with usefull commands in the future.