README.md lacks Community Support section

### What is this about?

## Summary

The current `README.md` file lacks a "Community Support" section with helpful links to:

- MetaMask Discord → https://discord.gg/metamask
- MetaMask Help Center → https://support.metamask.io

## Why it matters

New users looking for help may open GitHub Issues instead of using dedicated support channels, which leads to clutter in the issue tracker.

## Suggested fix

Add a "Community Support" section near the top of the README file with links to the two resources above and a short note recommending not to open Issues for general questions.

### Scenario

_No response_

### Design

_No response_

### Technical Details

_No response_

### Threat Modeling Framework

_No response_

### Acceptance Criteria

_No response_

### Stakeholder review needed before the work gets merged

- [ ] Engineering (needed in most cases)
- [ ] Design
- [ ] Product
- [ ] QA (automation tests are required to pass before merging PRs but not all changes are covered by automation tests - please review if QA is needed beyond automation tests)
- [ ] Security
- [ ] Legal
- [ ] Marketing
- [ ] Management (please specify)
- [ ] Other (please specify)

### References

_No response_

Open README.md and review the sections near the top to choose a suitable location. Add a Community Support section with the MetaMask Discord and Help Center links and a note directing general questions away from GitHub Issues; the work is done when both links and guidance are present.

Written by the indexing model from the issue text.