fix examples syntax

Author: dr-orlovsky

content/design.md

@@ -584,8 +584,8 @@ will become `ord` and acquire the opposite infix operator `<?`.
   category of its composed input type to category of its composed output type.</p>
 </aside>
 
-Functions can be equipped with generic arguments between colon separating function name from its input arguments,
-and `=>` character:
+Functions and data types can be equipped with generic arguments between colon separating function name from its input
+arguments, and `=>` character:
 
 ```
 fx len: T any, N unsigned => collection [T ^ $N..$N] -> N

content/examples.md

@@ -50,8 +50,8 @@ data Date: year Year, monthDay MonthDay
 
 Using generics:
 ```
-data Maybe: T any -> none | some(T)
-data Result: T any, E error -> ok(T) | err(E)
+data Maybe: T any => none | some(T)
+data Result: T any, E error => ok(T) | err(E)
 ```
 
 ### Functions
@@ -98,11 +98,11 @@ class iter => item any
     fx next: _ -> item?
 
 infx findFirst: V eq, I iter(item eq) => iter I, value V -> U64?
-    enumerate iter |> fst =?= value |? $ := lst _
+    enumerate iter |> fst =? value |? $ := lst _
 
 infx hasUnique: V eq, I iter(item eq) => iter I, value V -> Bool
     let index := iter findFirst value !! false
-    (iter[index..] |> =?= value |? $ := false) ?? true
+    (iter[index..] |> =? value |? $ := false) ?? true
     
 [0, 1, 2, 3, 4] hasUnique 1 -- true
 ```