enh: editor guide--update text around our on-hold process for packages where a maintainer hasn't responded in a period of time

[lwasser]

Allow a package review to remain open for up to a year (on hold) with 3 month check-ins following

The author can choose to have their submission put on hold (editor applies the holding label). The holding status will be revisited every 3 months, and after one year, the issue will be closed if no movement has occurred on the review.

[lwasser]

When this is implemented, i think we also want to add text for when a reviewer goes quiet. That if they odn't respnd in a month, we will let them know that we will look for another reviewer. (with some clauses around what happens if the review is actually complete). if the reviewer's review is complete there may be a way to evaluate it and move forward