Move os layer to be part of the core

src/os/shell/termcolour/termcolour.c

@@ -1,15 +0,0 @@
-#include "termcolour.h"
-#include "terminal_colours.h"
-
-void wapp_shell_termcolour_print_text(Str8RO *text, TerminalColour colour) {
-  if (colour < WAPP_TERM_COLOUR_FG_BLACK || colour > WAPP_TERM_COLOUR_FG_BR_WHITE) {
-    return;
-  }
-
-  print_coloured_text(text, colour);
-}
-
-void wapp_shell_termcolour_clear_colour(void) {
-  Str8RO empty = wapp_str8_lit_ro("");
-  print_coloured_text(&empty, WAPP_TERM_COLOUR_CLEAR);
-}