(feat): rename example-usage to just example

(feat): add the example's web-client dist folder to a gitignore
(fix): format issues
(fix): a lot of duplicate code

example-usage/client/src/main.rs

@@ -1,57 +0,0 @@
-mod auth;
-mod messages;
-
-use std::fs;
-use std::path::Path;
-
-use mtp::client::ClientConfig;
-use mtp::crypto::{KemPublicKey, PublicKeyBundle, SignaturePqPublicKey, SignaturePublicKey};
-
-fn dev_cert_path() -> String {
-    std::env::var("MTP_DEV_CERT").unwrap_or_else(|_| {
-        if Path::new("example-usage/dev-cert/cert.pem").exists() {
-            "example-usage/dev-cert/cert.pem".to_string()
-        } else {
-            "dev-cert/cert.pem".to_string()
-        }
-    })
-}
-
-#[tokio::main]
-async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let cert_path = dev_cert_path();
-    let cert_pem = fs::read(&cert_path).unwrap_or_else(|e| {
-        panic!(
-            "Missing TLS certificate at {cert_path}: enter the Nix shell first or run the server to generate it: {e}"
-        )
-    });
-    let host_public_key = PublicKeyBundle::new(
-        KemPublicKey::new(
-            fs::read("host_enc_kem_pk.bin")
-                .expect("Missing host_enc_kem_pk.bin: run server first"),
-        ),
-        SignaturePqPublicKey::new(
-            fs::read("host_sig_pq_pk.bin")
-                .expect("Missing host_sig_pq_pk.bin: run server first"),
-        ),
-        SignaturePublicKey::new(
-            fs::read("host_sig_pk.bin").expect("Missing host_sig_pk.bin: run server first"),
-        ),
-    );
-
-    println!("Connecting to 127.0.0.1:8080 ...");
-
-    let config = ClientConfig {
-        url: "https://127.0.0.1:8080".into(),
-        server_cert: Some(cert_pem),
-        client_id: 0,
-    };
-
-    let server_bundle = host_public_key.clone();
-    let (conn, keyring) =
-        auth::connect_or_register(config, host_public_key, "client_keys.json").await?;
-    messages::send_and_receive(&conn, &keyring, &server_bundle).await?;
-
-    println!("\nDone");
-    Ok(())
-}