docs: use markdown for readme file

README.md

@@ -0,0 +1,5 @@
+
+# pyCOREPOS
+
+A Python interface to the [CORE POS](https://github.com/CORE-POS)
+system.

README.rst

@@ -1,7 +0,0 @@
-
-pyCOREPOS
-=========
-
-A Python interface to the `CORE POS`_ system.
-
-.. _CORE POS:  https://github.com/CORE-POS

pyproject.toml

@@ -8,7 +8,7 @@ build-backend = "hatchling.build"
 name = "pyCOREPOS"
 version = "0.3.0"
 description = "Python Interface to CORE POS"
-readme = "README.rst"
+readme = "README.md"
 authors = [{name = "Lance Edgar", email = "lance@edbob.org"}]
 license = {text = "GNU GPL v3+"}
 classifiers = [