Describe timestamp format

[OttoAllmendinger]

"Timestamps" are actually kind of a tree-like structure encoded in the binary format. Operations are edges between nodes, the leafs are "Attestations".

It should be possible to describe them as a language grammar in a couple of tables.

Unfortunately there is no such prose description, only the code to go by:

https://github.com/opentimestamps/python-opentimestamps/blob/master/opentimestamps/core/timestamp.py (Timestamp.deserialize)