fix readme

README.md

@@ -31,7 +31,6 @@ A collection of commonly used Smithy shapes.
   - [alloy#nullable](#alloynullable)
   - [alloy#defaultValue](#alloydefaultvalue)
   - [alloy#dataExamples](#alloydataexamples)
-  - [alloy#openEnum](#alloyopenenum)
   - [alloy#structurePattern](#alloystructurepattern)
   - [alloy.openapi](#alloyopenapi)
     - [alloy.openapi#openapiExtensions](#alloyopenapiopenapiextensions)
@@ -493,27 +492,6 @@ structure User {
 }
 ```
 
-### alloy#openEnum
-
-Specifies that an enumeration is open meaning that it can accept "unknown" values that are not explicitly specified inside of the smithy enum shape definition.
-This trait should be mainly be used for interop with external libraries that require it. Often a string or integer type may be more applicable if there are many different
-possible values that the API can return.
-
-This trait can be applied to `enum` or `intEnum` shapes.
-
-```smithy
-@openEnum
-enum Shape {
-  SQUARE, CIRCLE
-}
-
-@openEnum
-intEnum IntShape {
-  SQUARE = 1
-  CIRCLE = 2
-}
-```
-
 ### alloy#structurePattern
 
 The `alloy#structurePattern` trait provides a way to specify that a given `String` will conform to a provided format and that it should be parsed into a `Structure` rather than a `String`. For example: