fix: slightly better trigger dir management

include/pipeline.h

@@ -38,6 +38,7 @@ typedef struct {
 
 // create a new pipeline_conf struct instance based on a configuration line.
 optional_pipeline_conf pipeline_create(const char* config_line);
+void pipeline_destroy(pipeline_conf* conf);
 void pipeline_register(pthread_t thread);
 void pipeline_loop();