Update Product.swift to render the api description correctly (#6879)

* Update Product.swift to render the api description correctly

* [ADD] Added indent to align parameters

Author: Jaesung

Sources/PackageDescription/Product.swift

@@ -132,8 +132,7 @@ public class Product {
     ///     don't support both linkage types, use
     ///     ``Product/Library/LibraryType/static`` or
     ///     ``Product/Library/LibraryType/dynamic`` for this parameter.
-    ///
-    ///  - targets: The targets that are bundled into a library product.
+    ///   - targets: The targets that are bundled into a library product.
     ///
     /// - Returns: A `Product` instance.
     public static func library(