docs: fix incorrect freezeTime flag in time freezing guide

[Preksha0401]

What has changed?

This PR fixes incorrect usage of the time freezing CLI flag in the Time Freezing documentation.
Replaced --freeze-time with the correct --freezeTime flag in the Docker-related sections to ensure consistency with the Keploy CLI.

Fixes #3510

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
• Documentation update (if none of the other choices apply).

How Has This Been Tested?

This is a documentation-only change. No local testing was required.

Checklist:

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.