add an outline of the structure of the node
//! `start` subcommand - entry point for starting a zebra node
+//!
+//! ## Application Structure
+//!
+//! A zebra node consists of the following services and tasks:
+//!
+//! * Network Service
+//! * primary interface to the node
+//! * handles all external network requests for the zcash protocol
+//! * provides an interface to the rest of the network for other services and
+//! tasks running within this node
+//! * Consensus Service
+//! * handles all validation logic for the node
+//! * verifies blocks using zebra-chain and zebra-script, then stores verified
+//! blocks in zebra-state
+//! * Sync Task
+//! * This task runs in the background and continouously queries the network for
+//! new blocks to be verified and added to the local state
use crate::config::ZebradConfig;
use crate::{components::tokio::TokioComponent, prelude::*};
use abscissa_core::{config, Command, FrameworkError, Options, Runnable};
