All hexified strings must be lower case

The documentation should state at all relevant places that hexified strings (e.g hexified hashes, hexified signatures) used in the transactions and in the batches must be lower case (i.e. using 0-9, a-f and not 0-9, A-F).

You stumble on this issue if you program clients not using the Sawtooth provided SDKs and you use your own hexifier (this means that one potential place to add this information is in: docs/source/app_developers_guide/no_sdk.rst).

Failing that, some commands will succeed and others not.

For example, I succeeded in getting transactions accepted with upper cased hex, in having them visible in the sawtooth transaction list command but not able to execute the sawtooth transaction show on the resulting transaction ID because show cannot work with transaction IDs containing upper case letters A-F.

This change is valid for all versions of the documentation.