Rat Chat specific item blocking it for its priority location

[skidznet]

if the rat cannot reach a priority location because an item is blocking progression, it can say that in chat. currently it just says it cannot reach it without giving info about why it cannot.

[airbreather]

Related: together with #119, also consider incorporating any hints that it has into this.

be careful to strike a good balance between "not too spammy" and "talkative enough to be useful"

[Arenes214]

There could be a "(at)rat bkstatus" command that displays the item(s) needed so that the chat isn't spammed