Revise replace-type schema and remove structname

Updated the schema for the `#!yaml replace-type:` parameter and removed the `structname` parameter.

Author: LandonTClipp

docs/v3.md

@@ -160,11 +160,6 @@ Mockery v2 provided a `keeptree` parameter that was deprecated and used only in
 
 The `#!yaml replace-type:` parameter has an updated schema. In v2, [users provided a list of strings](https://vektra.github.io/mockery/latest-v2/features/#replace-types), where each string needed to confirm to a specific format that was parsed at runtime. In v3, the [schema is more explicit](replace-type.md) to make it simpler.
 
-
-### `#!yaml structname:`
-
-The `structname` parameter has been replaced with `structname`.
-
 ### `#!yaml resolve-type-alias:`
 
 In v2, `resolve-type-alias` was set to `True` by default to retain backwards compatibility. In v3, this is permanently set to `False`.