SDK docs ref cli (#2741)

Closes https://github.com/paritytech/polkadot-sdk-docs/issues/53

docs/sdk/src/reference_docs/cli.rs

-//! # Command Line Arguments
+//! # Substrate CLI
 //!
+//! Let's see some examples of typical CLI arguments used when setting up and running a
+//! Substrate-based blockchain. We use the [`substrate-node-template`](https://github.com/substrate-developer-hub/substrate-node-template)
+//! on these examples.
 //!
-//! Notes:
+//! #### Checking the available CLI arguments
+//! ```bash
+//! ./target/debug/node-template --help
+//! ```
+//! - `--help`: Displays the available CLI arguments.
 //!
-//! - Command line arguments of a typical substrate based chain, and how to find and learn them.
-//! - How to extend them with your custom stuff.
+//! #### Starting a Local Substrate Node in Development Mode
+//! ```bash
+//! ./target/release/node-template \
+//! --dev
+//! ```
+//! - `--dev`: Runs the node in development mode, using a pre-defined development chain
+//!   specification.
+//! This mode ensures a fresh state by deleting existing data on restart.
+//!
+//! #### Generating Custom Chain Specification
+//! ```bash
+//! ./target/debug/node-template \
+//! build-spec \
+//! --disable-default-bootnode \
+//! --chain local \
+//! > customSpec.json
+//! ```
+//!
+//! - `build-spec`: A subcommand to generate a chain specification file.
+//! - `--disable-default-bootnode`: Disables the default bootnodes in the node template.
+//! - `--chain local`: Indicates the chain specification is for a local development chain.
+//! - `> customSpec.json`: Redirects the output into a customSpec.json file.
+//!
+//! #### Converting Chain Specification to Raw Format
+//! ```bash
+//! ./target/debug/node-template build-spec \
+//! --chain=customSpec.json \
+//! --raw \
+//! --disable-default-bootnode \
+//! > customSpecRaw.json
+//! ```
+//!
+//! - `--chain=customSpec.json`: Uses the custom chain specification as input.
+//! - `--disable-default-bootnode`: Disables the default bootnodes in the node template.
+//! - `--raw`: Converts the chain specification into a raw format with encoded storage keys.
+//! - `> customSpecRaw.json`: Outputs to customSpecRaw.json.
+//!
+//! #### Starting the First Node in a Private Network
+//! ```bash
+//! ./target/debug/node-template \
+//!   --base-path /tmp/node01 \
+//!   --chain ./customSpecRaw.json \
+//!   --port 30333 \
+//!   --ws-port 9945 \
+//!   --rpc-port 9933 \
+//!   --telemetry-url "wss://telemetry.polkadot.io/submit/ 0" \
+//!   --validator \
+//!   --rpc-methods Unsafe \
+//!   --name MyNode01
+//! ```
+//!
+//! - `--base-path`: Sets the directory for node data.
+//! - `--chain`: Specifies the chain specification file.
+//! - `--port`: TCP port for peer-to-peer communication.
+//! - `--ws-port`: WebSocket port for RPC.
+//! - `--rpc-port`: HTTP port for JSON-RPC.
+//! - `--telemetry-url`: Endpoint for sending telemetry data.
+//! - `--validator`: Indicates the node’s participation in block production.
+//! - `--rpc-methods Unsafe`: Allows potentially unsafe RPC methods.
+//! - `--name`: Sets a human-readable name for the node.
+//!
+//! #### Adding a Second Node to the Network
+//! ```bash
+//! ./target/release/node-template \
+//!   --base-path /tmp/bob \
+//!   --chain local \
+//!   --bob \
+//!   --port 30334 \
+//!   --rpc-port 9946 \
+//!   --telemetry-url "wss://telemetry.polkadot.io/submit/ 0" \
+//!   --validator \
+//!   --bootnodes /ip4/127.0.0.1/tcp/30333/p2p/12D3KooWEyoppNCUx8Yx66oV9fJnriXwCcXwDDUA2kj6vnc6iDEp
+//! ```
+//!
+//! - `--base-path`: Sets the directory for node data.
+//! - `--chain`: Specifies the chain specification file.
+//! - `--bob`: Initializes the node with the session keys of the "Bob" account.
+//! - `--port`: TCP port for peer-to-peer communication.
+//! - `--rpc-port`: HTTP port for JSON-RPC.
+//! - `--telemetry-url`: Endpoint for sending telemetry data.
+//! - `--validator`: Indicates the node’s participation in block production.
+//! - `--bootnodes`: Specifies the address of the first node for peer discovery. Nodes should find
+//!   each other using mDNS. This command needs to be used if they don't find each other.
+//!
+//! ---
+//!
+//! > If you are interested in learning how to extend the CLI with your custom arguments, you can
+//! > check out the [Customize your Substrate chain CLI](https://www.youtube.com/watch?v=IVifko1fqjw)
+//! > seminar.
+//! > Please note that the seminar is based on an older version of Substrate, and [Clap](https://docs.rs/clap/latest/clap/)
+//! > is now used instead of [StructOpt](https://docs.rs/structopt/latest/structopt/) for parsing
+//! > CLI arguments.