chore: update m4g key cap material

Author: andy23512

src/app/const/cross-reference.consts.ts

@@ -255,4 +255,7 @@ export const CROSS_REFERENCES = {
   ccu_key_cap_dependence: [
     'You can customize the key caps of CCU, and this spec will depend on the shape of the key caps.',
   ],
+  m4g_key_cap: [
+    'The key caps on M4G was made of rubber X-ring and 3D-printed plastic. The latest ones are made of molded and textured rubber.',
+  ],
 } satisfies Record<CrossReferenceKey, CrossReferenceContent>;

src/app/const/device.consts.ts

@@ -79,7 +79,11 @@ const M4G: Device = {
       value: '3D-printed Plastic',
       crossReference: 'm4g_base_material',
     },
-    keyCap: 'Rubber X-Ring + 3D-printed Plastic',
+    keyCap: {
+      type: 'string',
+      value: 'Molded and Textured Rubber',
+      crossReference: 'm4g_key_cap',
+    },
   },
   other: {
     pointingDevice: {

src/app/model/cross-reference.model.ts

@@ -38,4 +38,5 @@ export type CrossReferenceKey =
   | 'cc1_key_travel'
   | 'cc2_mounting_hole_depth'
   | 'ccu_externals_dependence'
-  | 'ccu_key_cap_dependence';
+  | 'ccu_key_cap_dependence'
+  | 'm4g_key_cap';