docs: fix a typo for static files provider

[AnishDe12020]

What does this PR address?

Before submitting:

• Make sure to follow GitHub's guide on creating PR.
• Did you read through contribution guidelines?
• Did your changes require updates to the documentation? Have you updated those accordingly?
• Did you write tests to cover your changes? Did it pass locally when running cargo test?
• Have you run cargo fmt, cargo check and cargo clippy locally to ensure that CI passes?

Didn't run the cargo commands as it was a docs update

Note: i feel like it is a grammatical mistake, I may be wrong (about 90% sure it is one though)

[coffee-cup]

😄