Add temporary root node

[jeloagnasin]

Fixes #123

[iamacup]

I merged PR #63 into my fork here: iamacup#14

I think this fixes #123 ...

I renamed my fork to react-native-markdown-display on npm because unfortunately the maintainer of this lib hasn’t been able to approve pull requests for quite some time.

[jeloagnasin]

@iamacup, thank you so much for continuing the work! Looking forward to your fork.

[mientjan]

Thank you for the contribution! The v4.0.0 architecture handles this differently with the rootRenderRule in AstRenderer.tsx. Closing as the v4 approach addresses the underlying need.