Refactor KEYMAPS(...) macro

This refactors the KEYMAPS(...) macro and factors out
a header and footer portion that are now define as individual
macros START_KEYMAPS and END_KEYMAPS. The original
KEYMAPS(...) macro now relies on the newly defined macros.

The newly introduced macros enable keymap definitions that
allow for macro definitions between the start and end part
which is not possible inside the KEYMAPS(...) macro invocation.

Signed-off-by: Florian Fleissner <florian.fleissner@inpartik.de>

src/kaleidoscope/layers.h

@@ -22,18 +22,26 @@
 #include KALEIDOSCOPE_HARDWARE_H
 #include "kaleidoscope_internal/device.h"
 
+#define START_KEYMAPS                                                   __NL__ \
+   const Key keymaps_linear[][kaleidoscope_internal::device.matrix_rows * kaleidoscope_internal::device.matrix_columns] PROGMEM = {
+
+#define END_KEYMAPS                                                     __NL__ \
+   };                                                                   __NL__ \
+   uint8_t layer_count                                                  __NL__ \
+      = sizeof(keymaps_linear) / sizeof(*keymaps_linear);               __NL__ \
+                                                                        __NL__ \
+   /* This deprecated compatibility wrapper is removed by the linker if __NL__ \
+      it is not accessed nowhere.                                       __NL__ \
+   */                                                                   __NL__ \
+   kaleidoscope::internal::Keymaps2DInterface keymaps;
+
 // Macro for defining the keymap. This should be used in the sketch
 // file (*.ino) to define the keymap[] array that holds the user's
 // layers. It also computes the number of layers in that keymap.
-#define KEYMAPS(layers...)				                                    __NL__ \
-  const Key keymaps_linear[][kaleidoscope_internal::device.matrix_rows * kaleidoscope_internal::device.matrix_columns] PROGMEM = { layers };           __NL__ \
-  uint8_t layer_count                                                   __NL__ \
-     = sizeof(keymaps_linear) / sizeof(*keymaps_linear);                __NL__ \
-                                                                        __NL__ \
-  /* This deprecated compatibility wrapper is removed by the linker if  __NL__ \
-     it is not accessed nowhere.                                        __NL__ \
-  */                                                                    __NL__ \
-  kaleidoscope::internal::Keymaps2DInterface keymaps;
+#define KEYMAPS(layers...)                                              __NL__ \
+  START_KEYMAPS                                                         __NL__ \
+     layers                                                             __NL__ \
+  END_KEYMAPS
 
 extern uint8_t layer_count;