I just got an invite, for those interested in tracking waves of invites

Yup.

would it be a good idea to have a short summary of a topic (e.g. max 10 lines that inform the reader in a super-summarized form what the topic is all about)?

I've been using docs-beta for 10 minutes and I haven't figured out a way to do this

Probably, if it's not lazy … But make it a standard thing? I doubt that.

For now maybe just put a tl;dr section at the top?

an example, it would be nice to put a 1-line explanation of what "template metaprogramming" means in its general form, since might sound so cryptic for a newcomer

Anybody wanna create the 'haxe' tag?

@MarcoA. docs-beta.stackexchange.com/documentation/javascript/282/… here's a 'Syntax' part, summarising without words.

Quick question: is this still the private beta?

@nneonneo yes

Just got mine. Thanks for the birthday present :D

@Adam Thanks. I am one of them who got the invitations.