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

.claude/skills/artifact/templates/TM.md

@@ -0,0 +1,30 @@
+# @TITLE@
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | @ID@ |
+| CrossReference | @CROSSREF@ |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| @DATE@ | Proposed | @AUTHOR@ | <reviewer S-ID> | Initial version | pending |
+
+---
+
+## Purpose
+
+Tracks backward/forward links between artifact instances so that the Business Case's
+cross-artifact traceability success criterion is measurable. A row is added or
+updated whenever an artifact instance is created or reviewed.
+
+## Traceability Table
+
+| Artifact Instance | Type | Language | Domain | Upstream (Backward Link) | Downstream (Forward Link) | Last Reviewed (RC-ID) |
+| --- | --- | --- | --- | --- | --- | --- |
+| [<ID>] | <type> | <Language row, or - for a technical type> | <Domain row, or -> | [<upstream-ID>] | [<downstream-ID>] | [<RC-ID>] |
+
+---
+
+@LINKS@