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

src/pretty_table/constants.py

@@ -0,0 +1,20 @@
+"""!
+@file constants.py
+@brief Constants of the Pokemon table: column titles and the rows shown.
+"""
+
+## Title of the column holding the Pokemon name.
+COLUMN_NAME: str = "Pokemon Name"
+
+## Title of the column holding the Pokemon type.
+COLUMN_TYPE: str = "Type"
+
+## Column titles in display order.
+COLUMN_TITLES: tuple[str, str] = (COLUMN_NAME, COLUMN_TYPE)
+
+## Pokemon names in display order, paired with their type.
+POKEMON: tuple[tuple[str, str], ...] = (
+    ("Pikachu", "Electric"),
+    ("Squirtle", "Water"),
+    ("Charmander", "Fire"),
+)