update: update contributor docs

[0xmovses]

Pull Request

Description

• This contribution represents a trivial change (skip the following sections).
• This contribution represents a CI/CD change that needs to be tested e2e (skip the following sections; justify below).

Motivation and Context

Adds the git submodule update --init --recursive command to our docs.

Changes Made

Testing

Screenshots (if applicable)

Related Issues

Checklist

• I have read and followed the project's contributing guidelines.
• I have tested the changes thoroughly.
• My code follows the style and formatting guidelines of the project.
• I have updated the relevant documentation, if applicable.
• I have added tests, if appropriate.
• The code builds without any errors or warnings.
• All existing tests pass successfully.

Additional Notes