Add example for mnemonic account creation

This example is special as it requires a python dependency.

https://github.com/trezor/python-mnemonic

As examples are in the main package, the dependency is added in the package.

changed milestone to %1.0.0

added Examples label

mentioned in commit 6d25289e

mentioned in merge request !142 (merged)

marked this issue as related to #161 (closed)

Duplicate #161 (closed).

added Authentication Crypto duplicate labels

mentioned in commit 41d674e8

Sorry, I close the issuer to use the #161 (closed).

closed