Group macros by topic, add Blobifier, fix first tool change

- Split the macro files into folders by topic (print, heating, afc,
  pressure_advance, spoolman, leds, sensors); klipper-macros.cfg is the
  one file printer.cfg includes. Macros moved unchanged; the effective
  config is identical apart from the paths of the PA shell scripts.
- Add the modified Blobifier (Turtleblobifier for AFC) and define
  [save_variables] once in save_variables.cfg instead of in both
  blobifier.cfg and the PA macros (same file, bd_pa_variables.cfg).
- PRINT_WARMUP: heat to the loaded lane's temperature before the first
  tool change. AFC skips heating when the loaded lane's tool number is
  not in the print file's temperature list, and the unload then failed
  below min_extrude_temp.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

macros/print/homing.cfg

@@ -0,0 +1,8 @@
+# HOME: home all axes and move to the bed centre
+
+[gcode_macro HOME]
+gcode:
+    G90
+    G4 P2000
+    G28 X0 Y0 Z0
+    G1 X175 Y175 Z10 F1200