Remove MetNet references from documentation (Issue #352)

[Dhyey58]

Pull Request

Description

This PR removes remaining MetNet references from the documentation to align with PR #346 which previously removed the MetNet features. This cleanup ensures documentation accurately reflects the current state of the codebase.

Changes made:

1. Removed metnet/ from the directory tree in README.md
2. Removed metnet_preprocessor reference from ocf_datapipes/transform/xarray/README.md

Motivation: Keep documentation in sync with codebase changes, preventing confusion for new contributors.

Fixes #352

How Has This Been Tested?

• Yes
  The changes are documentation-only. I have verified that:

1. All MetNet references have been removed from the specified files
2. No other documentation was accidentally modified
3. Performed a grep search to confirm no other MetNet references remain

If your changes affect data processing, have you plotted any changes? i.e. have you done a quick sanity check?

• Yes
  Not applicable as these are documentation-only changes.

Checklist:

• My code follows OCF's coding style guidelines
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
  (N/A - documentation only changes)

[Dhyey58]

Hi team,

I noticed that there are some test failures in the CI pipeline for Python 3.10 and 3.11. Here's some context:

1. This PR addresses issue strip out metnet tests #352 by:

   • Removing remaining documentation references to MetNet
   • The actual MetNet tests and features were already removed in PR rm metnet #346
   • Changes made:
     • Removed metnet/ reference from main README.md
     • Removed metnet_preprocessor reference from ocf_datapipes/transform/xarray/README.md

2. Investigation results:

   • Verified that no MetNet test files remain in the codebase
   • No test files or configurations were modified in this PR
   • The pre-commit CI check passed successfully
   • The current test failures appear unrelated to these documentation changes

Could you please advise:

1. Are these test failures known issues?
2. Should these failures be addressed in this PR, or would they be better handled separately?

Thank you for your guidance!

[AUdaltsova]

ocf_datapipes have now been deprecated, so I'll close this PR.