TSX Toggle in Docs

[nicknisi]

It would be nice to have a HyperScript/TSX toggle on the tutorials to allow readers who prefer one style over the other to view the examples in that format.

[bitranch]

If you commit to adding the toggle, I'd suggest a comment next to the toggle saying that tsx is not the preferred method.

Otherwise, I fear that this will lead down the same sort of path that the dojo 1 declarative syntax went -- where people discover they have to rethink and refactor their code when they find out that declarative isn't actually the fastest or best way to build an app.