Doc updated: Image component Focal Picker needs default settings

[faisal-alvi]

Description of the Change

This PR simply adds a note in the readme file for the image block component that default settings must be added when a focalPoint is used. Also capitalizes the first character in the description column.

Closes #182

How to test the Change

1. Add component as outlined in the readme
2. Add your attributes to block.json

{
  ...
  "attributes": {
    "imageId": {
      "type": "number"
    },
    "focalPoint": {
      "type": "object"
    }
  }
}

3. See that the Focal Picker should render.

Changelog Entry

Updated - Document for an image component, mentioned that a focal picker needs default settings when used.

Credits

Props @colinswinney @faisal-alvi

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.

[fabiankaegy]

Thanks for these updates :)

I think we can merge this in as is. As a follow up I would like to actually change the implementation in the Image component to automatically have a fallback value for the focal point in place so that this is no longer an issue.

[faisal-alvi]

That is exactly what I thought earlier but then it seems like we also need to handle the onChangeFocalPoint's fallback function. So I skipped it and just changed the readme. :)

[fabiankaegy]

@faisal-alvi I created #184