Could you kindly enlighten me on whether Ledger, the renowned hardware wallet provider, offers support for Polkadot, the innovative blockchain network? I'm particularly interested in knowing if Ledger devices allow users to securely store and manage Polkadot tokens. Additionally, I'm also curious if there are any specific Ledger models that are compatible with Polkadot or if there are any known limitations or challenges in using Ledger with Polkadot. Thank you in advance for your clarification on this matter.