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/US.md

@@ -0,0 +1,38 @@
+# @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 and Scope
+
+## Story List
+
+### @ID@.01 — <short title>
+
+**As a** <actor from [UCD-<n>]>, **I want** <goal>, **so that** <benefit>.
+
+**Acceptance Criteria**
+
+- Given <context>, when <action>, then <observable outcome>.
+
+| Traces to | Size | INVEST exceptions |
+| --- | --- | --- |
+| [UC-<n>] or [MIL-<n>] | fits one iteration | none |
+
+## INVEST Check
+
+---
+
+@LINKS@