feature: add public brokerage integration

[Romazes]

Description

Adds the Public.com brokerage to the CLI command reference (README.md). The change is the scripts/readme.py output regenerated from the updated modules-1.14.json: Public is added to the --brokerage and --data-provider-historical choice lists, and the --public-secret-key / --public-account-number options are documented for lean live and lean cloud live deploy.

Related PR(s)

• Brokerage plugin: https://github.com/QuantConnect/Lean.Brokerages.Public

Related Issue

N/A

Motivation and Context

The Public.com brokerage plugin is implemented and needs to be selectable from the CLI. This mirrors the Webull integration (#645), which added the brokerage to the same command reference.

Requires Documentation Change

This is the documentation change. The modules-1.14.json file is maintained separately (it is gitignored in this repo and shared with the team for review), so it is not part of this PR.

How Has This Been Tested?

• Ran python scripts/readme.py; the diff is limited to README.md.
• Public appears in --brokerage and --data-provider-historical.
• Public is absent from --data-provider-live: Public.com has no real-time market-data stream, so the brokerage advertises no data-queue-handler capability (Subscribe/Unsubscribe throw NotSupportedException).
• Prompted keys match PublicBrokerageFactory.BrokerageData: public-secret-key, public-account-number.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Refactor (non-breaking change which improves implementation)
• Performance (non-breaking change which improves performance)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Non-functional change (xml comments/documentation/etc)

Checklist:

• My code follows the code style of this project.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My branch follows the naming convention bug-<issue#>-<description> or feature-<issue#>-<description>