docs: the ARNITECH_BLADE option and the mc64blade configuration

NOTICE

@@ -54,6 +54,20 @@ Changes:
   src/kernal/arnitech/ff00.arnitech_jumptable.s, CONFIG.md (2026-10-18): version 2 of the
   Arnitech jump table, with JMPs from $FF0C that reset a Network Card's CS8900A at the
   RR-Net socket, copy its MAC address, and send and receive Ethernet frames through it.
+- src/,,config_mc64blade.s (new), Makefile (2026-10-18): a second configuration, mc64blade,
+  the Firmware of arnitech's Blades: the mc64 one with its own config ID ($6E), the brand
+  "MC64 BLADE", no tape, programmable keys, joystick cursor, panic screen, or feature list, and
+  ARNITECH_BLADE on; targets build/kernal_mc64blade.rom and build/basic_mc64blade.rom.
+- src/aliases/,aliases_hardware_arnitech.s, src/kernal/arnitech/arnitech_terminal.s,
+  arnitech_native.s, arnitech_autoboot.s (new), src/kernal/screen/*, src/kernal/keyboard/*,
+  src/kernal/init/*, src/kernal/iostack/e50a.plot.s, f157.chrin.s, f1ca.chrout.s,
+  src/kernal/interrupts/*, src/kernal/time/udtim.s, src/kernal/iec/iec_wait1ms.s,
+  src/basic/init/basic_cold_start_internal.s, src/basic/,imports.s, CONFIG.md (2026-10-18): a
+  new option, ARNITECH_BLADE, on in the mc64blade configuration only. It leaves out the screen
+  editor, the keyboard matrix scan, the VIC-II set-up, PAL detection, and the Cartridge checks;
+  the screen and the keyboard are an Arnitech Terminal Card, the serial bus's 1 ms wait counts
+  on CIA #1's timer B, CINT puts handlers for a 65816's native-mode interrupts under the KERNAL,
+  and BASIC's cold start loads and runs the first program on device 8.
 - NOTICE: this file.
 
 The licence terms are unchanged; see LICENSE, COPYING, and COPYING.LESSER.