add dev notes

R/application/check_dependency/dependency_graph.R

@@ -0,0 +1,5 @@
+#' try to extract the dependency graph from the application modules
+#' 
+const dependency_graph = function() {
+
+}

R/application/hook.R

@@ -2,6 +2,8 @@
 #'
 #' @param app the app object which is generated via the ``app`` function
 #' 
+#' @details the application module will be add to the ``context$workflow`` tuple list.
+#' 
 const hook = function(app) {
     const context   = .get_context();
     const pool      = context$workflow;