[activitystreams] Issue: Default Language Context MAY -> SHOULD marked as i18n

r12a has just labeled an issue for 
https://github.com/w3c/activitystreams as "i18n":

== Default Language Context MAY -> SHOULD ==
This is a comment on https://github.com/w3c/activitystreams/pull/352 
(raised here so that i18n folks are notified).

The section Default Language Context says:

> When using [[JSON-LD]] mechanisms to produce or consume Activity 
Streams 2.0 documents, the @language property MAY be used within a 
@context to identify the default language. This mechanism may not be 
understood by implementations that do not choose to process Activity 
Streams 2.0 documents using JSON-LD. 

We were previously explaining that associating language with strings 
is often necessary when it comes to presenting them to a user (eg. to 
prevent Chinese users being presented with Japanese font glyphs).  
Could we either change MAY to SHOULD, or at least add a note to say 
that actually language information is quite important (since very few 
developers seem to recognise that)?

See https://github.com/w3c/activitystreams/issues/354