show default size for mnemonic --size using 'ToText' instance

[KtorZ]

Issue Number

#357

Overview

• I have used 'showT' instead of 'show' to get a correct output for the default size

Comments

Before:

Usage: cardano-wallet mnemonic generate [--size INT]
  Generate English BIP-0039 compatible mnemonic words.

Available options:
  -h,--help                Show this help text
  --size INT               number of mnemonic words to generate. (default: MS_15)

After:

Usage: cardano-wallet-http-bridge mnemonic generate [--size INT]
  Generate English BIP-0039 compatible mnemonic words.

Available options:
  -h,--help                Show this help text
  --size INT               number of mnemonic words to generate. (default: 15)