DOCSP-35883 fix collision typo (#6066)

Author: jeff-allen-mongo

source/core/indexes/index-types/index-hashed.txt

@@ -46,7 +46,7 @@ Floating-Point Numbers
 
 Hashed indexes truncate floating-point numbers to 64-bit integers before
 hashing. For example, a hashed index uses the same hash to store the
-values ``2.3``, ``2.2``, and ``2.9``. This is a **collison**, where
+values ``2.3``, ``2.2``, and ``2.9``. This is a **collision**, where
 multiple values are assigned to a single hash key. Collisions may
 negatively impact query performance.