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

tests/test_constants.py

@@ -0,0 +1,17 @@
+"""Tests for the constants."""
+
+from pretty_table import constants
+
+
+def test_column_titles_match_the_column_constants() -> None:
+    assert constants.COLUMN_TITLES == (constants.COLUMN_NAME, constants.COLUMN_TYPE)
+
+
+def test_pokemon_includes_the_lesson_examples() -> None:
+    assert ("Pikachu", "Electric") in constants.POKEMON
+    assert ("Squirtle", "Water") in constants.POKEMON
+
+
+def test_pokemon_names_are_unique() -> None:
+    names = [name for name, _ in constants.POKEMON]
+    assert len(names) == len(set(names))