chore(docs): small grammar fix on the landing page (#3989)

# Description

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*



## Additional Context



## Documentation\*

Check one:
- [ ] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[Exceptional Case]** Documentation to be submitted in a separate
PR.

# PR Checklist\*

- [ ] I have tested the changes locally.
- [ ] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

docs/src/pages/index.jsx

@@ -38,7 +38,7 @@ export default function Landing() {
           </h1>
           <p className="homepage_p">
             Noir is a Domain Specific Language for SNARK proving systems. It has been designed to use any ACIR
-            compatible proving system. It's design choices are influenced heavily by Rust and focuses on a simple,
+            compatible proving system. Its design choices are influenced heavily by Rust and focuses on a simple,
             familiar syntax.
           </p>