chore: add new /help functions (#14)

templates/telegram/help.html

@@ -28,7 +28,9 @@
 - /wallet_unlink <chain> <address> - unlink your wallet
 - /validator_link <chain> <address> - subscribe to a validator
 - /validator_unlink <chain> <address> - unsubscribe from a validator
+- /wallets - see the wallets you have linked
 - /balance - see the balances, rewards, delegations etc. of the wallets you are subscribed to
 - /chains - see the list of chains this wallet uses
+- /chain <chain> - see chain info, denoms, explorers and LCD hosts
 - /chain_bind <chain> - bind a chain to this chat
 - /chain_unbind <chain> - unbind a chain from this chat