JSX: Improved spread operator in tag attributes

[0xc14m1z]

This is a small tweak of tag regexes that allow spaces within the brackets of spread operator.

[RunDevelopment]

Looks good!
Just one nit: There can be any number of spaces between ... and the variable.

Also, the spread expression can be any valid JS expression or is it really just [a-z_$][\w$]*(?:\.[a-z_$][\w$]*)* ? So e.g. is <div {...foo.bar('baz')}></div> valid?

[0xc14m1z]

First of all, thanks for considering my PR.
Then, I followed your suggestion and allowed for any number of spaces between the dots and the expression.

Regarding your question... no. It doesn't take account for javascript expression after the .... This PR is intended as a tweak for the spaces.

Considered the README though, where small and focused PR are preferred to multi-feature ones, I think that making expressions to work should be another PR. I tried here and it doesn't work.

[RunDevelopment]

Thank you for contributing!

And thanks for your answer. I just wanted to know. Making a pattern which allows any JS expression is extremely tricky, so I'll do that myself :)