Allow reserved words as tags, e.g. `{{class}}`

[Rich-Harris]

See #289 (comment) (creating a new issue as that one was closed and this is slightly different).

[dmitry-kurmanov]

Hi team! What about {{class}} in svelte v2.14.1 . I can't find it in the doc. Thank you.

PS I think that div wrapper with class is ok, so it is just interest.

[Conduitry]

@dmitrykurmanov I'm not sure what you're asking. You can still do {class} or other reserved words in current versions. (The syntax changed from {{class}} to {class} in v2.) Because of challenged with parsing, you can only have tags that contain just a reserved word, and they can't be part of a larger expression.

What specifically are you saying you think should be in the docs?

[dmitry-kurmanov]

@Conduitry please forgot about it :). It is an old issue about passing class to the nested component. With an old syntax. I've missed it. I am ok now and don't have any problem with it. Sorry for the confusing question.