Update proposals/NNNN-global-actor-isolated-types-usability.md

Co-authored-by: John McCall <[email protected]>

Author: simanerush

proposals/NNNN-global-actor-isolated-types-usability.md

@@ -13,7 +13,7 @@ This proposal encompasses a collection of changes to concurrency rules concernin
 
 ## Motivation
 
-Currently, there exist limitations in the concurrency model around global-isolated-types. 
+Currently, there exist limitations in the concurrency model around types that are isolated to global actors.
 
 First, let's consider rules for properties of global-isolated value types. The first limitation is that `var` properties of such value types cannot be declared `nonisolated`. This poses a number of problems, for example when implementing a protocol conformance. The current workaround is to use the `nonisolated(unsafe)` keyword on the property: