Update 'Customizations'

Customizations.md

@@ -101,6 +101,7 @@ Slayer:
 Summoning:
 - Summoning points have changed. A familiar's lifespan will not decrease while you have more than zero summoning points, meaning you can maintain the same familiar indefinitely as long as you keep your points topped up.
 	- This also means you no longer need summoning points to summon/renew a familiar, but the timer will start instantly. The points you used to spend to summon a familiar have been added to the drain rate. The drain rate is now (summoning level required)/(familiar lifespan). Example: a Thorny Snail requires level 13 summoning, and has a lifespan of 16 minutes, so it will drain 13 points every 16 minutes.
+- Exp is gained every minute a familiar is summoned. The amount is the summoning level required for that familiar, plus ten.
 - Making pouches now only costs 1 Spirit Shard per pouch, regardless of pouch type.
 - Beast of Burden familiars will automatically pick up items dropped by enemies, if they have room. Beasts of Burden are: Thorny Snail, Spirit Kalphite, Bull Ant, Spirit Terrorbird, War Tortoise, Pack Yak.
 	- The Pack Yak, if it has its special move scrolls in its inventory, will automatically use those scrolls to deposit dropped items to your bank.