docs: fix 'allows to rewrite' grammar in rewrite storage middleware

Description

In docs/content/storage-drivers/middleware/rewrite.md:

A storage middleware which allows to rewrite the URL returned by the storage driver.

Non-idiomatic English: "allows to rewrite" should be "allows rewriting" (or "allows you to rewrite").

Proposed fix

allows to rewrite → allows rewriting

Docs-only; happy to open a PR.