Function proposal_create 

pub fn proposal_create(
    accounts: ProposalCreateAccounts,
    args: ProposalCreateArgs,
    program_id: Option<Pubkey>,
) -> Instruction

Creates a new multisig proposal. Example:

use squads_multisig::solana_program::pubkey::Pubkey;
use squads_multisig::solana_program::system_program;
use squads_multisig::state::ConfigAction;
use squads_multisig::client::{
    ProposalCreateAccounts,
    ProposalCreateArgs,
    proposal_create
};

let ix = proposal_create(
    ProposalCreateAccounts {
        multisig: Pubkey::new_unique(),
        creator: Pubkey::new_unique(),
        proposal: Pubkey::new_unique(),
        rent_payer: Pubkey::new_unique(),
        system_program: system_program::id(),
    },
    ProposalCreateArgs {
        transaction_index: 0,
            draft: false,
    },
    Some(squads_multisig_program::ID)
);