Some additional info to the sync doc

docs/sync.markdown

@@ -1,28 +1,32 b''
 # INTRO #
 
 This document discribes the server sync protocol.
 
 # DRAFT PROTOCOL DESCRIPTION #
 
 Version:
 * Protocol version
 * Model version
 
 Node data:
 * Public key
 
 Object data:
 * Post
 * Post list (for sync)
 
 The node requests other node's changes list since some time (since epoch if
 this is the start). The other node sends a list of post ids or posts in the
 XML or JSON format.
 
 Protocol version is the version of the sync api. Model version is the version
 of data models. If at least one of them is different, the sync cannot be
 performed.
 
 The node signs the data with its key. The receiving node saves the key at the
 first sync and checks it every time. If the key has changed, the info won't be
 saved from the node (or the node id must be changed).
+
+Each node holds a list of networks it wants to get info from.
+
+Each post has an ID in the unique format: node-id/post-id