add application key footnote

docs/docs/codes/_footnotes/ios-application.mdx

@@ -0,0 +1,2 @@
+Keycode is registered, but has no visible effect in tested apps (Gmail, Safari, Notes)
+iPhone 6 / iOS 12.4.6

docs/src/data/footnotes.js

@@ -7,9 +7,11 @@
 import example from "@site/docs/codes/_footnotes/example.mdx";
 import iosPower from "@site/docs/codes/_footnotes/ios-power.mdx";
 import macosPower from "@site/docs/codes/_footnotes/macos-power.mdx";
+import iosApplication from "@site/docs/codes/_footnotes/ios-application.mdx";
 
 export default {
   example,
   iosPower,
   macosPower,
+  iosApplication,
 };

docs/src/data/hid.js

@@ -2670,7 +2670,9 @@ export default [
       macos: true,
       ios: true,
     },
-    footnotes: {},
+    footnotes: {
+      ios: ["iosApplication"],
+    },
   },
   {
     names: ["K_POWER", "K_PWR"],