docs(fix): ledger_wallet single line docker build

[leet4tari]

Description Document a single line docker command for ledger_wallet firmware build

Motivation and Context Easy to follow instructions

How Has This Been Tested? Tested run command locally

What process can a PR reviewer use to test or verify this change?

Breaking Changes

• [x] None
• [ ] Requires data directory on base node to be deleted
• [ ] Requires hard fork
• [ ] Other - Please specify