Add Pretty Table project: plan, accepted documents and code

Business Case, Stakeholder Analysis, Project Plan and milestone MIL-001
with review records RC-001 to RC-003, then the Python project: PrettyTable
Pokemon table, constants, pytest tests, pyproject.toml, Doxyfile, CI
workflow and README.

Task: MIL-001#1
Task: MIL-001#2
Task: MIL-001#3
Task: MIL-001#4
Task: MIL-001#5
Task: MIL-001#6
Task: MIL-001#7
Task: MIL-001#8

.agents/skills/artifact/templates/BC.md

@@ -0,0 +1,72 @@
+# @TITLE@
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | @ID@ |
+| CrossReference | @CROSSREF@ |
+| Language | @LANGUAGE@ |
+| Domain | @DOMAIN@ |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| @DATE@ | Proposed | @AUTHOR@ | <reviewer S-ID> | Initial version | pending |
+
+---
+
+## Executive Summary
+
+## Methodological and Standards Foundation
+
+## Problem Statement
+
+## Business Opportunity
+
+## Objectives
+
+## Scope
+
+### In Scope
+
+### Out of Scope
+
+## Expected Benefits
+
+### Tangible Benefits
+
+### Intangible Benefits
+
+## Strategic Alignment
+
+## Success Criteria
+
+| # | Criterion | Target | Measure |
+| --- | --- | --- | --- |
+
+## Risks
+
+| Risk | Impact | Mitigation |
+| --- | --- | --- |
+
+## Assumptions
+
+## Constraints
+
+## Cost–Benefit Assessment
+
+| Costs | Benefits |
+| --- | --- |
+
+## Stakeholders
+
+| Stakeholder ID (SA) | Interest in this project |
+| --- | --- |
+
+## Recommendation
+
+<Proceed | Do not proceed> — <one-sentence rationale>
+
+---
+
+@LINKS@