information about anonymisation in the template

[cpmpercussion]

We should have information about anonymisation in the template as suggested by @YichenWangs

We haven't included "anonymise.sty" anymore, but the acmart class includes "anonymous" mode.

So for papers authors would use: \documentclass[sigconf,anonymous]{nimeart}

and music/workshops: \documentclass[acmsmall,anonymous]{nimeart}

This makes the author names invisible but you can also hide text in the paper like this:

\begin{anonsuppress}
This is the continuation of the previous work by the author
\cite{prev1, prev2}.
\end{anonsuppress}

This work was performed at \anon{NSA}.
This work was performed at \anon[No Such Agency]{NSA}.

(both examples from the acmart manual)