add Haskell snippet for Either monad to handle errors in computations

Author: ACR1209

snippets/haskell/monads/either-monad.md

@@ -0,0 +1,20 @@
+---
+title: Either Monad for Error Handling
+description: Using the Either monad to handle errors in a computation.
+author: ACR1209
+tags: haskell, monads, either, error handling
+---
+
+```hs
+safeDiv :: Int -> Int -> Either String Int
+safeDiv _ 0 = Left "Division by zero error"
+safeDiv x y = Right (x `div` y)
+
+main :: IO ()
+main = do
+    let result = do
+            a <- safeDiv 10 2
+            b <- safeDiv a 0  -- This will trigger an error
+            return b
+    print result  -- Output: Left "Division by zero error"
+```