fix(build): modernize package exports, tooling configuration, and test setup

ts/index.ts

@@ -7,11 +7,11 @@ export let yamlStringToObject = async (
 };
 
 export let objectToYamlString = async (
-  objectArg
+  objectArg: unknown
 ): Promise<string> => {
   return plugins.yaml.stringify(objectArg);
 };
 
 export let getYamlDocFromString = async (stringArg: string) => {
   return plugins.yaml.parseDocument(stringArg);
-}
+};