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/UC.md

@@ -0,0 +1,57 @@
+# @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 |
+
+---
+
+**Format:** Brief | Casual | Fully Dressed  (delete the unused sections below)
+
+## Brief
+
+<one paragraph: main success scenario only>
+
+## Casual
+
+<informal multi-paragraph narrative; may mention some alternate flows>
+
+## Fully Dressed
+
+- **Scope:** <system>
+- **Level:** summary | user-goal | subfunction
+- **Primary Actor:** <actor, as named in [UCD-<n>]>
+- **Stakeholders and Interests:**
+  - <S-ID> — <interest>
+- **Preconditions:**
+- **Postconditions (success guarantee):**
+
+### Main Success Scenario
+
+1. <actor action>
+2. <system response>
+
+### Extensions (Alternative / Exception Flows)
+
+- 2a. <condition>:
+  1. <handling> (`<<include>>` / `<<extend>>` <other use case>)
+
+### Special Requirements / Business Rules
+
+| Step | Rule |
+| --- | --- |
+
+### Open Issues
+
+---
+
+@LINKS@