chore(packages): add more docs and improve types

packages/shared/src/utils/string.ts

@@ -1,3 +1,8 @@
+/**
+ * Uncapitalizes the first letter of a string
+ * @param str The string to uncapitalize
+ * @returns The uncapitalized string
+ */
 export function uncapitalize<T extends string>(str: T): Uncapitalize<T> {
     return (str.charAt(0).toLowerCase() + str.slice(1)) as Uncapitalize<T>
 }