Add support to new version of flutter quill

[Rohitbagul003]

Currently the latest version of flutter quill is flutter_quill: ^7.2.14 which is not working with this delta_markdown version so please update this to newer version

[fdemiguel]

Here is another person interested in having this library updated to be used with the latest version of flutter_quill.

Thanks

[andreykuzmenko]

+1

[neganngdev]

+1

[aiyubinx]

+1

[Luismi74]

+1