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/PP.md

@@ -0,0 +1,63 @@
+# @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 |
+
+---
+
+## Purpose
+
+<what this plan schedules, and over what constraint>
+
+## Planning Assumptions
+
+- Week 1 starts <date>; the plan ends by <date>, per the Business Case constraint.
+- Phase length: <e.g. two weeks>.
+
+## Gateway Schedule
+
+| Gateway | Document | Window | Decision date | Owner | Stories | Main deliverable | Milestone |
+| --- | --- | --- | --- | --- | --- | --- | --- |
+| <name> | [MIL-<n>] | <dates> | <date> | <S-ID> | <US-…> | <deliverable> | <link once synced> |
+
+```plantuml
+@startgantt
+Project starts <start YYYY-MM-DD>
+[Phase 1] starts <start YYYY-MM-DD> and ends <end YYYY-MM-DD>
+[Phase 1 Go/No-Go] happens <date YYYY-MM-DD>
+@endgantt
+```
+
+## Scope Coverage
+
+| Business Case scope item | Gateway |
+| --- | --- |
+
+## Dependencies
+
+```
+<phase 1> → <phase 2> → ...
+```
+
+## Plan Risks
+
+| Risk | Impact | Mitigation |
+| --- | --- | --- |
+
+## Open Issues
+
+- <unresolved item>
+
+---
+
+@LINKS@