feat(striker-ui-api): add cap function

striker-ui-api/src/lib/cap.ts

@@ -0,0 +1,4 @@
+export const cap = (
+  value: string,
+  { locales }: { locales?: string | string[] } = {},
+) => `${value[0].toLocaleUpperCase(locales)}${value.slice(1)}`;