Add mouse buttons 4/5

docs/en/mouse_keys.md

@@ -15,6 +15,8 @@ keyboard.modules.append(MouseKeys())
 | `KC.MB_LMB`               | Left mouse button                    |
 | `KC.MB_RMB`               | Right mouse button                   |
 | `KC.MB_MMB`               | Middle mouse button                  |
+| `KC.MB_BTN4`              | mouse button 4                       |
+| `KC.MB_BTN5`              | mouse button 5                       |
 | `KC.MW_UP`                | Mouse wheel up                       |
 | `KC.MW_DOWN`, `KC.MW_DN`  | Mouse wheel down                     |
 | `KC.MS_UP`                | Move mouse cursor up                 |

kmk/modules/mouse_keys.py

@@ -28,6 +28,14 @@ class MouseKeys(Module):
             names=('MB_RMB',),
             code=2,
         )
+        make_mouse_key(
+            names=('MB_BTN4',),
+            code=8,
+        )
+        make_mouse_key(
+            names=('MB_BTN5',),
+            code=16,
+        )
         make_key(
             names=('MW_UP',),
             on_press=self._mw_up_press,