Fix textTheme deprecation and null safety issue

[maheshj01]

deprecation fix as per https://docs.flutter.dev/release/breaking-changes/3-19-deprecations

[maheshj01]

Anyone awaiting for this fix to be merged you can add this to your pubspec.yaml

  feature_discovery:
    git:
      url: https://github.com/maheshj01/feature_discovery.git
      ref: master

[deakjahn]

Thanks but considering that there are almost a dozen outstanding PRs... Sad to see this abandoned.

[TheFe91]

@maheshmnj you should consider to publish your version to pub.dev with a new name maybe

[maheshj01]

@TheFe91 I don't think it would be right to publish someone else's work. Also, I can't promise any further updates to the package. But I can ensure this keeps running on future versions of flutter https://github.com/maheshmnj/feature_discovery.git

[richdreamalytics]

@ maheshj01 the packages has an MIT license, so it's fine republish, but I take your point about not being able to guarantee future support.