SLua editor: Support highlighting Moonwave style multi-line comments (as comments)

[canny]

Tokens are --[=[ ]=], doesn't highlight correctly, but saves fine.

--[=[

  Changed event handler

  https://wiki.secondlife.com/wiki/Changed

  @param change number -- bit field of CHANGED_* flags	

]=]

function changed(change: number)

  ll.OwnerSay(`change called with {change}`)

end

https://eryn.io/moonwave/docs/TagList

http://lua-users.org/wiki/StringsTutorial (see nesting quotes section)

https://secondlife.canny.io/admin/board/slua-alpha/p/support-highlighting-moonwave-style-multi-line-comments-as-comments

[canny]

This issue has been linked to a Canny post: Support highlighting Moonwave style multi-line comments (as comments) 🎉

[canny]

This issue has been linked to a Canny post: multi line strings [[string]] within say commands compile correctly but are syntax highlighted 🎉

[marchcat]

Multi-line strings should also be highlighted correctly.

function default()
    ll.Say(0, [[in string default for]])
end
default()

https://feedback.secondlife.com/slua-alpha/p/multi-line-strings-string-within-say-commands-compile-correctly-but-are-syntax-h