Add a src/tools dir to show exports

src/tools/capitalize.ts

@@ -0,0 +1,5 @@
+/** @see <https://docs.tsafe.dev/capitalize> */
+export function capitalize<S extends string>(str: S): Capitalize<S> {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    return (str.charAt(0).toUpperCase() + str.slice(1)) as any;
+}

src/tools/index.ts

@@ -0,0 +1 @@
+export * from "./capitalize";