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

Doxyfile

@@ -0,0 +1,16 @@
+# Doxygen configuration. Run `doxygen Doxyfile` from the repository root.
+PROJECT_NAME           = "Pretty Table"
+PROJECT_BRIEF          = "Udemy 100 Days of Code: Pokemon type table with PrettyTable"
+OUTPUT_DIRECTORY       = docs/doxygen
+INPUT                  = src README.md
+USE_MDFILE_AS_MAINPAGE = README.md
+FILE_PATTERNS          = *.py *.md
+RECURSIVE              = YES
+OPTIMIZE_OUTPUT_JAVA   = YES
+EXTRACT_ALL            = YES
+EXTRACT_PRIVATE        = NO
+GENERATE_HTML          = YES
+GENERATE_LATEX         = NO
+QUIET                  = YES
+WARN_IF_UNDOCUMENTED   = YES
+WARN_AS_ERROR          = NO