Getting started with MyBB 1.9 development - Composer

[Euan T]

Regarding memory usage: note that we have Twig running in debug mode at the moment which is likely having an impact, but makes it easier for us during development.

Prefixes probably need a "|raw" applied, or the rendering moved into a Twig function.

Thanks for the testing for definite though, I've created an issue: https://github.com/mybb/mybb/issues/3294