[activities] remove note about persistent instances. delete some whitespace. (#7671)

Author: afgiel

docs/activities/design-patterns.mdx

@@ -141,8 +141,7 @@ Monetization in Activities will be available soon. Keep the following considerat
 
 ### Activities close when the last participant in the Activity leaves it
 - The next time the Activity is launched, even if it’s in the same DM or Voice Channel, it will be a different instance and could have different participants.
-- Note: This behavior will change in 2024, when we release persistent instances.
-        
+
 ### If a game is launched, what % of the time do users reach different phases of the game?
 - This includes launch → start, as there can be a large dropoff between these two (especially if you don’t support solo play or small group sizes).
 - This also includes various check points in the game, including what % of sessions that start a game reach the end of that game!
@@ -151,10 +150,10 @@ Monetization in Activities will be available soon. Keep the following considerat
 - If drop-off is really high at a certain point, see if you can figure out why or change flows.
 
 ### How many games are played in a session?
-- More games per session isn’t inherently better (you may have an Activity that is meant to be one long game), but is a good baseline to understand. 
+- More games per session isn’t inherently better (you may have an Activity that is meant to be one long game), but is a good baseline to understand.
 - If you expect to see a lot of repeat plays per session and don’t, it can be worth digging in to understand more.
 
-### How does the group size impact various key metrics? 
+### How does the group size impact various key metrics?
 - For example, are larger sessions more or less likely to reach the end of a game? To replay? Etc.
 - This can help you catch if your Activity has unexpected weak points in different group sizes — maybe the game drags on if there are too many people or isn’t compelling enough if there’s only two.
 - Not every Activity needs to be built for robust group sizes, but if you have the option to play with X # of players, it’s good practice to make sure that experience is enjoyable for all involved!