refactor: common error interface for avsRegistry chainReader

CHANGELOG.md

@@ -13,4 +13,16 @@ Each version will have a separate `Breaking Changes` section as well. To describ
 * fix: change requested pr url in changelog's workflow by @maximopalopoli in <https://github.com/Layr-Labs/eigensdk-go/pull/575>
 
 ### Breaking changes
+* refactor: add custom error struct in avs registry reader methods by @maximopalopoli in <https://github.com/Layr-Labs/eigensdk-go/pull/486>
+  * The errors now follow this format: `error name (error code) - error description: underlying error`.
+
+    For example, in this code section:
+    ```go
+	if r.serviceManager == nil {
+		wrappedError := elcontracts.MissingContractError("ServiceManager")
+		return nil, wrappedError
+	}
+    ```
+    The returned error if err is not nil would be `Missing needed contract (1) - ServiceManager contract not provided` (this error type has no underlying error)
+
 ### Removed