Adjust TypeScript example

[ktsn]

Close #44

@HerringtonDarkholme Can you check this? :)

[HerringtonDarkholme]

The code and README look good to me.

But I just remember why the original TypeScript version is written in render function. Because we want to use runtime build and it works with other Vue plugins.
Will it be misleading to change to full build? I have seen a lot of problems caused by pointing to wrong build in webpack config.

Edit: since our README example has already used template I think this might not be problematic, or it is at most as problematic as babel's version.

[ktsn]

Yes, the difference of runtime/standalone build often causes the problem for beginners. But I also think using template is more natural as example because the most users would use template for ordinary components.
Since the docs and warning message is well provided now, I think we do not have to worry about that too much.

[ktsn]

@HerringtonDarkholme Thanks!