add error case for too small terminal window

src/main.c

@@ -286,6 +286,8 @@ int main(int argc, char **argv) {
         int y,x;
         getmaxyx(stdscr, y, x);
         if (y < 42 || x < 100) {
+                endwin();
+                perror("terminal window too small");
                 return 1;
         }