Restructure CONTRIBUTING.md and add pull request template (Skillware-style)

[rosspeili]

Problem Statement

CONTRIBUTING.md is a short overview (bug/feature/PR bullets, design philosophy, CI mention). Skillware's contributing guide is the single entry point: contribution-type table, fork/upstream sync commands, universal expectations (scope, changelog, tests), PR process, and links to testing + agent workflow + PR template.

Rooms has no .github/PULL_REQUEST_TEMPLATE.md. Reviewers repeat the same asks (tests, changelog, rebase, git email). New contributors (including agents) lack a checklist aligned with our labels (session-logic, cli, testing, etc.).

Proposed Solution

1. Rewrite CONTRIBUTING.md with Skillware-inspired sections (adapted for Rooms — no skill registry):

   • Navigation table
   • Ways to contribute table: core framework (rooms/), CLI wizard (cli.py / rooms/cli.py), settings YAML, docs, tests, good first issue
   • Getting started: fork, upstream remote, branch naming feat/issue-N-short-desc
   • Universal expectations: scope discipline, match existing style, when to update CHANGELOG, git author email must be GitHub-verified (see Feat preflight check  #43 contributor attribution lesson)
   • Pull request process: link issue, local verify commands, push to fork, CI green
   • Related documents table linking ARCHITECTURE, EXAMPLES, TESTING, CHANGELOG, agent workflow doc (separate issue)

2. Add .github/PULL_REQUEST_TEMPLATE.md with:

   • Type of change (bug / feature / docs / session-logic / CLI)
   • Checklist: tests, flake8, CHANGELOG if user-visible, settings example YAML if schema changes
   • Related issues (Fixes #N)

3. Cross-link from README Documentation Library.

Acceptance criteria

• CONTRIBUTING.md covers fork workflow, test commands, changelog policy, git email note
• PR template exists and matches Rooms contribution types
• No Skillware-specific content (skills/, manifest.yaml) copied verbatim

Alternatives Considered

• CONTRIBUTING only, no PR template — weaker; template reduces review friction.
• Single AGENTS.md instead of expanding CONTRIBUTING — rejected; humans and agents both need CONTRIBUTING as hub (Skillware pattern).

Priority

Medium 🟡

Additional Context

Skillware refs: CONTRIBUTING.md, .github/PULL_REQUEST_TEMPLATE.md.

Can be split across two PRs (docs first, template second) but one issue is fine.