Documentation: Minimal README documentation

README.md

@@ -1,3 +1,13 @@
 # PushPull
 
+A library of functions that could be useful for registering images. Note that code development is in its early stages and that many things will change.
+
+This package is not yet reistered as an official Julia package.
+If you are brave enouth to try using it, then the following may work:
+    using Pkg
+    Pkg.develop("https://github.com/spm/PushPull.jl")
+    using PushPull
+
+Note that the automated githib actions fail because there seems to be a problem in downloading the CUDA driver, leading on to several other problems.
+
 [![Build Status](https://github.com/spm/PushPull.jl/actions/workflows/CI.yml/badge.svg?branch=main)](https://github.com/spm/PushPull.jl/actions/workflows/CI.yml?query=branch%3Amain)