Fix AlphaFold release number

Update references to AlphaFold version

Merge pull request #27 from prehensilecode/update-2-3-1

Update for AlphaFold 2.3.1

Merge pull request #9 from prehensilecode/2.2.4

Update for AlphaFold 2.2.4

Merge pull request #5 from prehensilecode/cuda-path

Add CUDA utilities path

Merge pull request #5 from prehensilecode/cuda-path

Add CUDA utilities path

Merge pull request #3 from prehensilecode/update-for-2.2.2

Update for 2.2.2

Clarify instructions