Updated documentation. Cleaned up a bit.

- [doc] Updated the markdown documents for the v1.1 release.

- [doc] Removed references to classic GUI mode.

grbl/report.c

@@ -394,9 +394,6 @@ void report_build_info(char *line)
   #ifdef ALLOW_FEED_OVERRIDE_DURING_PROBE_CYCLES
     serial_write('A');
   #endif
-  #ifdef USE_CLASSIC_GRBL_INTERFACE
-    serial_write('R');
-  #endif
   #ifndef ENABLE_RESTORE_EEPROM_WIPE_ALL // NOTE: Shown when disabled.
     serial_write('*');
   #endif