Implement defaultValue on inputs and textarea

[dretsa]

Tabler looks great but there is a problem with implementing forms with it. In some use cases one might want to use the defaultValue prop on input and textarea elements.

There has been a pull request for this already: #515 #495

I understand that v2 is under active development and priority but it would be nice to be able to use this prop in v1. Is there a particular reason why it's not implemented? I would be happy to implement it and make a pull request with all the proper contribution guidelines.