update README

Author: MasonProtter

README.md

@@ -2,8 +2,7 @@
 
 StableTasks is a simple package with one main API `StableTasks.@spawn` (not exported by default). 
 
-It works like `Threads.@spawn`, except it is *type stable* to `fetch` from (and it does not yet support threadpools
-other than the default threadpool).
+It works like `Threads.@spawn`, except it is *type stable* to `fetch` from.
 
 ``` julia
 julia> Core.Compiler.return_type(() -> fetch(StableTasks.@spawn 1 + 1), Tuple{})