MIL-001 Repository foundation: baseline documents, project configuration, CI and Doxyfile

Business Case, Stakeholder Analysis, Project Plan and MIL-001 accepted
with review records; ADR-0001 and ADR-0002; pyproject.toml, .gitignore,
package skeleton, Doxyfile and Gitea CI workflow.

Task: MIL-001#1
Task: MIL-001#2
Task: MIL-001#3
Task: MIL-001#4
Task: MIL-001#5
Task: MIL-001#6

.yamllint.yml

@@ -0,0 +1,8 @@
+# yamllint configuration for the repository's YAML files (tool: yamllint).
+extends: default
+rules:
+  line-length:
+    max: 100
+  truthy:
+    check-keys: false
+  document-start: disable