fix: update Sui environment setup (#18303)

## Description 

PR #17253 moved the location of the Sui environment setup file. This PR
adjusts sources to changes.

## Test plan 

Checked the doc.

---

## Release notes

Check each box that your changes affect. If none of the boxes relate to
your changes, release notes aren't required.

For each box you select, include information after the relevant heading
that describes the impact of your changes that a user might notice and
any actions they must take to implement updates.

- [ ] Protocol: 
- [ ] Nodes (Validators and Full nodes): 
- [ ] Indexer: 
- [ ] JSON-RPC: 
- [ ] GraphQL: 
- [ ] CLI: 
- [ ] Rust SDK:

Signed-off-by: Emmanuel Ferdman <[email protected]>

CONTRIBUTING.md

@@ -4,7 +4,7 @@ Thanks for considering making a contribution to the Sui network or its documenta
 
 ## Contribute to Sui
 
-See [Sui Environment Setup](https://github.com/MystenLabs/sui/blob/main/docs/content/guides/developer/getting-started/sui-environment.mdx) for approach to submitting code fixes and enhancements.
+See [Sui Environment Setup](https://github.com/MystenLabs/sui/blob/main/docs/content/references/contribute/sui-environment.mdx) for approach to submitting code fixes and enhancements.
 
 If you want to contribute code that creates a feature on Sui, start with a [Sui Improvement Proposal](https://github.com/sui-foundation/sips/tree/main) before developing the logic.