Add support for GeminiPR steno protocol.

This protocol breaks out "duplicate" keys into their own entry in the packet so that more complicated logic can be done on the software side, including support for additional languages and alternative theories.

quantum/keymap_extras/keymap_steno.h

@@ -18,8 +18,12 @@
 
 #include "keymap.h"
 
+// List of keycodes for the steno keyboard. To prevent
+// errors, this must be <= 42 total entries in order to
+// support the GeminiPR protocol.
 enum steno_keycodes {
-  STN_FN  = QK_STENO,
+  STN__MIN = QK_STENO,
+  STN_FN  = STN__MIN,
   STN_NUM,
   STN_N1 = STN_NUM,
   STN_N2,
@@ -65,7 +69,8 @@ enum steno_keycodes {
   STN_NA,
   STN_NB,
   STN_NC,
-  STN_ZR
+  STN_ZR,
+  STN__MAX = STN_ZR, // must be less than QK_STENO_BOLT
 };
 
 #endif