Add E092.

[julianmorley]

Tiny tweak to add a validation error that was missed in the initial pass.

[zimeon]

Well spotted! I wonder whether we would best best to restructure the first sentence to include the name of the file in the MUST for E058, otherwise that MUST will be basically meaningless/uncheckable. We could say:

Every occurrence of an inventory file [E058]MUST have an accompanying sidecar file named inventory.json.ALGORITHM stating its digest, where ALGORITHM is the chosen digest algorithm for the object. The ALGORITHM [E059]MUST match the value given for the digestAlgorithm key in the inventory. An example might be inventory.json.sha512.

[zimeon]

Have created #448 to debate change to remove this MUST but agree change proposed here is correct given the current text