Replace old array syntax with new one in docs

[bocharsky-bw]

I believe better to use new array syntax [] in the docs. In other code we'll left old one array() for BC.
What do you think?

[richsage]

Yep - I don't have a preference either way. Those people using earlier versions will (hopefully) recognise the newer syntax!

[bocharsky-bw]

OK, after the all my open docs PRs are merged I could create a new one for it.

[richsage]

Looks good! :-)