Fix guard example (#45)

Author: spicydonuts

package.json

@@ -6,7 +6,7 @@
     "test": "pulp test"
   },
   "devDependencies": {
-    "pulp": "^10.0.4",
+    "pulp": "^12.0.1",
     "purescript-psa": "^0.5.0-rc.1",
     "rimraf": "^2.6.1"
   }

src/Control/MonadZero.purs

@@ -47,9 +47,9 @@ instance monadZeroArray :: MonadZero Array
 -- | factors :: Int -> Array Int
 -- | factors n = do
 -- |   a <- 1..n
--- |   b <- a..n
+-- |   b <- 1..n
 -- |   guard $ a * b == n
--- |   pure [a, b]
+-- |   pure a
 -- | ```
 guard :: forall m. MonadZero m => Boolean -> m Unit
 guard true = pure unit