feat(controllers): add detailed comment to getBySlugCategory function

The `getBySlugCategory` function in `category.controller.ts` now has a detailed comment. The comment includes a description of the function, its parameters, and its return value.

Signed-off-by: Mathis <yidhra@tuta.io>

src/controllers/category.controller.ts

@@ -118,7 +118,15 @@ async function getAllCategory(res: Response): Promise<Response> {
 	});
 }
 
-async function getBySlugCategory(req: Request, res:Response) {
+/**
+ * Get category by slug
+ *
+ * @param {Request} req - The request object containing category slug
+ * @param {Response} res - The response object to send back the category
+ *
+ * @return {Promise<Response>} - The response with category data or error message
+ */
+async function getBySlugCategory(req: Request, res:Response): Promise<Response> {
 	const categorySlug = req.params["categorySlug"];
     if (!categorySlug) {
       logger.error("Category slug is missing");