build: Add all necessary files for the build system

All basic files for testing, building and distributing the project
are added here. The Makefile can set up the virtual environment and
create different package types from the project.

MANIFEST.in

@@ -0,0 +1,10 @@
+recursive-include .reuse *
+recursive-include data *
+recursive-include LICENSES *
+include Makefile
+include MANIFEST.in
+include pyproject.toml
+include README.md
+include requirements.txt
+include setup.py
+recursive-include tests *