Rework "leaving early"

Changed the "What if a player needs to leave early" section into, "Does everyone need to be connected at the same time?"

This allows the FAQ to explain briefly what a sync multiworld and an async multiworld is.  This is probably good material for the Glossary, but it comes up so much in the Discord that we probably need to explain it here as briefly as possible.  This paragraph lends itself to the question of what to do if a player must leave early anyway.

WebHostLib/static/assets/faq/faq_en.md

@@ -49,7 +49,13 @@ As randomizers and multiworld randomizers have been around for a while now there
 and jargon that is used in conjunction by the communities surrounding them. For a lot of the terms that are more common
 to Archipelago and its specific systems please see the [Glossary](/glossary/en).
 
-## What happens if a person has to leave early?
+## Does everyone need to be connected at the same time?
+
+There are two different playstyles that are common for Archipelago multiworld sessions.  Multiworld sessions can either
+be considered synchronous (also known as a "sync" multiworld) where everyone connects and plays at the same time, or,
+a multiworld can be considered asynchronous (also known as an "async" multiworld) where players connect and play at
+their own pace.  The setup for each is identical.  The difference is how you and your friends choose to organize and
+play your multiworld.  Most groups decide on the format before creating their multiworld.
 
 If a player must leave early, they can use Archipelago's release system. When a player releases their game, all the
 items in that game which belong to other players are sent out automatically, so other players can continue to play.