docs(web): add opencode-md-table-formatter to ecosystem

[iMythms]

Issue for this PR

Closes #

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Adds @imythms/opencode-md-table-formatter to the ecosystem docs so users can discover and install the plugin from the official plugin list.

This is docs-only and does not change runtime behavior.

How did you verify your code works?

• Confirmed the change only updates packages/web/src/content/docs/ecosystem.mdx
• Verified the entry points to the correct plugin/repository reference
• No app/runtime code was changed

Screenshots / recordings

N/A (docs-only change)

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

Hey! Your PR title adding opencode-md-table-formatter by @imythms doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

No duplicate PRs found. The search results only return PR #15191 (the current PR itself) and other unrelated ecosystem documentation PRs for different plugins.

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍