BREAKING CHANGE(SmartAcme): Refactor challenge handling by removing legacy setChallenge/removeChallenge in favor of pluggable challengeHandlers and update documentation and tests accordingly

ts/smartacme.plugins.ts

@@ -37,3 +37,6 @@ export { tsclass };
 import * as acme from 'acme-client';
 
 export { acme };
+// local handlers for challenge types
+import * as handlers from './handlers/index.js';
+export { handlers };