add zip upload twingraph description to dataset upload

Author: lalepee

dataset/src/main/openapi/dataset.yaml

@@ -265,7 +265,34 @@ paths:
       tags:
         - dataset
       summary: Upload data from zip file to dataset's twingraph
-      description: Upload data from zip containing two folder 'edges' and 'nodes' themself containing nodes and edges as csv files.
+      description: |
+        To create a new graph from flat files,  you need to create a Zip file. This Zip
+        file must countain two folders named Edges and Nodes.
+
+        .zip hierarchy:
+        *main_folder/Nodes
+        *main_folder/Edges
+
+        In each folder you can place one or multiple csv files containing your Nodes or
+        Edges data.
+
+        Your csv files must follow the following header (column name) requirements:
+
+        The Nodes CSVs requires at least one column (the 1st).Column name = 'id'. It
+        will represent the nodes ID
+        Ids must be populated with string
+
+        The Edges CSVs require three columns named, in order,
+        * source
+        * target
+        * id
+
+        those colomns represent
+        * The source of the edge
+        * The target of the edge
+        * The id of the edge
+
+        All following columns content are up to you.
       requestBody:
         required: true
         content: