Revert "Improve forEachExample"

This reverts commit 58552d3.

because the whole point of the example was that it used forEach!

Closes: #74

Thanks to Hugo Peters for reporting

Author: tomjaguarpaw

bluefin-internal/src/Bluefin/Internal.hs

@@ -792,7 +792,7 @@ handleCoroutine update finish f = do
 --
 -- @
 -- >>> runPureEff $ yieldToList $ \\y -> do
---       for_ [0 .. 4] $ \\i -> do
+--       forEach (inFoldable [0 .. 3]) $ \\i -> do
 --         yield y i
 --         yield y (i * 10)
 -- ([0, 0, 1, 10, 2, 20, 3, 30], ())

bluefin-internal/src/Bluefin/Internal/Examples.hs

@@ -90,7 +90,7 @@ doubleNestedForEach f =
 
 forEachExample :: ([Int], ())
 forEachExample = runPureEff $ yieldToList $ \y -> do
-  for_ [0 .. 4] $ \i -> do
+  forEach (inFoldable [0 .. 4]) $ \i -> do
     yield y i
     yield y (i * 10)