Add a section for massa-client documentation

Nobody has claimed this yet.

```
HELP of Massa client (list of available commands):
- help no args: display this help
- exit no args: exit the prompt
- node_unban_by_ip IpAddr1 IpAddr2 ...: unban given IP address(es)
- node_unban_by_id Id1 Id2 ...: unban given id(s)
- node_ban_by_ip IpAddr1 IpAddr2 ...: ban given IP address(es)
- node_ban_by_id Id1 Id2 ...: ban given id(s)
- node_stop no args: stops the node
- node_get_staking_addresses no args: show staking addresses
- node_start_staking Address1 Address2 ...: starts staking with the given addresses
- node_stop_staking Address1 Address2 ...: stops staking with the given addresses
- node_testnet_rewards_program_ownership_proof Address discord_id: generate the testnet rewards program node/staker ownership proof
- node_bootstrap_whitelist (add, remove or allow-all) [IpAddr]: Manage bootstrap whitelist IP address(es). No args returns the bootstrap whitelist
- node_bootstrap_blacklist (add or remove) [IpAddr]: Manage bootstrap blacklist IP address(es). No args returns the bootstrap blacklist
- node_peers_whitelist (add or remove) [IpAddr]: Manage peers whitelist IP address(es). No args returns the peers whitelist
- get_status no args: show the status of the node (reachable? number of peers connected, consensus, version, config parameter summary...)
- get_addresses Address1 Address2 ...: get info about a list of addresses (balances, block creation, ...)
- get_datastore_entry Address Key: get a datastore entry (key must be UTF-8)
- get_blocks BlockId: show info about a block (content, finality ...)
- get_endorsements EndorsementId1 EndorsementId2 ...: show info about a list of endorsements (content, finality ...)
- get_operations OperationId1 OperationId2 ...: show info about a list of operations(content, finality ...)
- get_filtered_sc_output_event start=slot_period,slot_thread end=slot_period,slot_thread emitter_address=Address caller_address=Address operation_id=OperationId is_final=bool is_error=bool: show events emitted by smart contracts with various filters
- wallet_info show-all-keys: show wallet info (addresses, balances ...)
- wallet_get_public_key Address1 Address2 ..: get public key of the given addresses
- wallet_get_secret_key Address1 Address2 ...: get secret key of the given addresses
- wallet_generate_secret_key no args: generate a secret key and add it into the wallet
- wallet_add_secret_keys SecretKey1 SecretKey2 ...: add a list of secret keys to the wallet
- wallet_remove_addresses Address1 Address2 ...: remove a list of addresses from the wallet
- wallet_sign Address string: sign provided string with given address (address must be in the wallet)
- buy_rolls Address RollCount Fee: buy rolls with wallet address
- sell_rolls Address RollCount Fee: sell rolls with wallet address
- send_transaction SenderAddress ReceiverAddress Amount Fee: send coins from a wallet address
- execute_smart_contract SenderAddress PathToBytecode MaxGas Fee: create and send an operation containing byte code
- call_smart_contract SenderAddress TargetAddress FunctionName Parameter MaxGas Coins Fee: create and send an operation to call a function of a smart contract
- read_only_execute_smart_contract PathToBytecode MaxGas Address IsFinal: execute byte code, address is optional, is_final is optional. Nothing is really executed on chain
- read_only_call TargetAddress TargetFunction Parameter MaxGas SenderAddress IsFinal: call a smart contract function, sender address is optional, is_final is optional. Nothing is really executed on chain
- when_episode_ends no args: show time remaining to end of current episode
- when_moon no args: tells you when moon
```

Start by reviewing the documentation structure in this repository to find the appropriate location for a massa-client command reference. Use the command list in the issue as the source content, and consider the work done when the commands are presented in a clear documentation section.

Written by the indexing model from the issue text.