CU-8698x2k5b Fix read the docs builds (CogStack/MedCAT#538)

* CU-8698x2k5b: Add simple pyproject.toml

* CU-8698x2k5b: Make ReadTheDocs install with pip

Author: mart-r

medcat-v1/.readthedocs.yaml

@@ -15,5 +15,5 @@ sphinx:
 python:
   install:
     - requirements: docs/requirements.txt
-    - method: setuptools
-      path: .
+    - method: pip
+      path: .

medcat-v1/pyproject.toml

@@ -0,0 +1,5 @@
+[build-system]
+requires = ["setuptools>=42", "setuptools_scm[toml]>=6.2", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools_scm]