Add link to the documentation in the doc

src/login/KcContext.ts

@@ -5,6 +5,8 @@ import type { KcEnvName, ThemeName } from "../kc.gen";
 export type KcContextExtension = {
     themeName: ThemeName;
     properties: Record<KcEnvName, string> & {};
+    // NOTE: Here you can declare more properties to extend the KcContext
+    // See: https://docs.keycloakify.dev/faq-and-help/some-values-you-need-are-missing-from-in-kccontext
 };
 
 export type KcContextExtensionPerPage = {};