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/ADR.md

@@ -0,0 +1,42 @@
+# @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 |
+
+Allowed Status values: `Proposed`, `Accepted`, `Rejected`, `Deprecated`, `Superseded by ADR-NNNN`.
+
+---
+
+## Context
+
+<The forces/problem driving this decision, and the options considered.>
+
+## Decision
+
+<The decision that was made, stated plainly.>
+
+## Consequences
+
+**Positive:**
+
+- <positive consequence>
+
+**Negative:**
+
+- <negative consequence>
+
+## Affected Artifacts
+
+- [<ARTIFACT-ID>] — <how this decision affects it>, or a single "-" if none
+
+---
+
+@LINKS@