Use of sh:count

Through curation of shapes from SolidOS repositories for https://github.com/solid/shape-generation-artefacts:


- `sh:count 1;` was found in https://github.com/SolidOS/chat-pane/blob/main/shapes/chat-shapes.ttl
- sh:count is not part of  https://www.w3.org/TR/shacl/ 
- Replace with: 
`
sh:minCount 1;
sh:maxCount 1;
`

Original issue: https://github.com/solid/shape-generation-artefacts/issues/6




