surface callback since class is extendable publicly

Author: dmichon-msft

libraries/heft-config-file/src/ConfigurationFileBase.ts

@@ -393,6 +393,7 @@ interface IConfigurationFileCacheEntry<TConfigFile> {
 
 /**
  * Callback that returns a fallback configuration file path if the original configuration file was not found.
+ * @beta
  */
 export type IOnConfigurationFileNotFoundCallback = (
   resolvedConfigurationFilePathForLogging: string

libraries/heft-config-file/src/index.ts

@@ -22,6 +22,7 @@ export {
   type IJsonPathsMetadata,
   InheritanceType,
   type INonCustomJsonPathMetadata,
+  type IOnConfigurationFileNotFoundCallback,
   type IOriginalValueOptions,
   type IPropertiesInheritance,
   type IPropertyInheritance,