Fix old usage of UNICODE_MODE_MAC (qmk#22238)

docs/feature_unicode.md

@@ -140,7 +140,7 @@ To set the list of enabled input modes, add the `UNICODE_SELECTED_MODES` define
 ```c
 #define UNICODE_SELECTED_MODES UNICODE_MODE_LINUX
 // or
-#define UNICODE_SELECTED_MODES UNICODE_MODE_MAC, UNICODE_MODE_WINCOMPOSE
+#define UNICODE_SELECTED_MODES UNICODE_MODE_MACOS, UNICODE_MODE_WINCOMPOSE
 ```
 
 These modes can then be cycled through using the `UC_NEXT` and `UC_PREV` keycodes. You can also switch to any input mode, even if it is not specified in `UNICODE_SELECTED_MODES`, using their respective keycodes.
@@ -151,7 +151,7 @@ If your keyboard has working EEPROM, it will remember the last used input mode a
 
 ### ** macOS **
 
-**Mode Name:** `UNICODE_MODE_MAC`
+**Mode Name:** `UNICODE_MODE_MACOS`
 
 macOS has built-in support for Unicode input as its own input source. It supports all possible code points by way of surrogate pairs for code points above `U+FFFF`.