docs: Add opencode-architect to ecosystem documentation

[michalwarda]

What does this PR do?
Adds opencode-architect plugin to docs. What it is, when to use it, features.

I wanted an agent that truly knows the ins and outs of OpenCode, but the existing tooling kept producing subpar results. So I built OpenCode Architect: a plugin that bundles focused expert agents and stays synced with the freshest docs and guidelines, so developers can build better plugins, commands, skills, tools, and MCP integrations with confidence.

How did you verify your code works?
Not run (docs-only change).

[github-actions]

Hey! Your PR title Add opencode-architect to ecosystem documentation 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

[github-actions]

Closing this pull request because it has had no updates for more than 60 days. If you plan to continue working on it, feel free to reopen or open a new PR.