yampa: Adjust indentation to two spaces (KSG Haskell 1.3.0 - 4.2). Refs

#215.

Suggestion: Each time a new expression or block-like construct is opened, the
indent should increase by two spaces. When the section ends, the indent returns
to the previous indent level. The indent level applies to both Haskell
expressions and comments throughout the block.

yampa/src/FRP/Yampa/Basic.hs

@@ -70,7 +70,7 @@ b0 --> (SF {sfTF = tf10}) = SF {sfTF = \a0 -> (fst (tf10 a0), b0)}
 -- like the given sf.
 (-:>) :: b -> SF a b -> SF a b
 b0 -:> (SF {sfTF = tf10}) = SF {sfTF = \_a0 -> (ct, b0)}
- where ct = SF' $ \_dt a0 -> tf10 a0
+  where ct = SF' $ \_dt a0 -> tf10 a0
 
 -- | Input initialization operator.
 --
@@ -86,7 +86,7 @@ a0 >-- (SF {sfTF = tf10}) = SF {sfTF = \_ -> tf10 a0}
 -- time zero.
 (-=>) :: (b -> b) -> SF a b -> SF a b
 f -=> (SF {sfTF = tf10}) =
-    SF {sfTF = \a0 -> let (sf1, b0) = tf10 a0 in (sf1, f b0)}
+  SF {sfTF = \a0 -> let (sf1, b0) = tf10 a0 in (sf1, f b0)}
 
 -- | Transform initial input value.
 --