fix(guide): add better explanation of monad laws (#18490)

* add better explanation of monad laws

* remove 'simply' and 'just' from text

client/src/pages/guide/english/haskell/monad/index.md

@@ -5,7 +5,39 @@ title: Monad
 # Monad Laws
 There are 3 laws which must be satisfied by a data type to be considered as monad
 
+## Left Identity
+`return a >>= f` must equal `f a`
 
+This states that if we take a value and use `return` to put it in default context,
+then use `>>=` to feed it into a function, it's the same as applying the
+function to the original value.
+
+## Right Identity
+`m >>= return` must equal `m`
+This states that if we use `>>=` to feed a monadic value into return, we
+get back our original monadic value.
+
+## Associativity
+`(m >>= f) >>= g` must equal `m >>= (\x -> f x >>= g)`
+This allows us to chain together monadic function applications, regardless of
+how they are nested.
+
+This may seem obvious, and you may assume that it should work by default, but the
+associative law is required for this behavior
+
+# But what about `>>=` and `return`?
+Simple:
+
+`>>=`, or 'bind' takes a monad and a function that takes a value and returns a
+monad, and applies the function to a monad. This essentially allows us to
+manipulate data within monads, which can't be accessed by non-monadic functions.
+
+`return`, on the other hand, takes a value and returns a monad containing
+that value. Everything you could ever want to know about `return` is right
+there in the type signature:
+```haskell
+return :: a -> m a
+```
 
 # Maybe Monad