docs: add community resources section with Awesome UCP link

[onuratakan]

Description

Added a new "Community Resources" section to the README, including a link to the Awesome UCP repository. This provides users with easy access to a curated list of community-driven UCP resources, tools, and implementations.

Type of change

• Documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[onuratakan]

I signed the cla.

[wry-ry]

Thank you for your contribution to the Universal Commerce Protocol!

While we appreciate your enthusiasm for UCP, we are not officially endorsing any community resources at this time. We hope you continue to contribute to other areas of the project.