more docs

README.md

@@ -1,3 +1,7 @@
 # tower-github-webhook
 
 `tower-github-webhook` is a crate that simplifies validating webhooks received from GitHub.
+
+[![Crates.io](https://img.shields.io/crates/v/tower-github-webhook)](https://crates.io/crates/tower-github-webhook)
+[![Documentation](https://docs.rs/tower-github-webhook/badge.svg)](https://docs.rs/tower-github-webhook)
+[![Crates.io](https://img.shields.io/crates/l/tower-github-webhook)](tower-github-webhook/LICENSE)

src/layer.rs

@@ -1,12 +1,16 @@
 use crate::ValidateGitHubWebhook;
 use tower::Layer;
 
+/// Layer that applies the [ValidateGitHubWebhook] middleware which authorizes all requests using
+/// the `X-Hub-Signature-256` header.
 #[derive(Clone)]
 pub struct ValidateGitHubWebhookLayer<Secret> {
     webhook_secret: Secret,
 }
 
 impl<Secret> ValidateGitHubWebhookLayer<Secret> {
+    /// Authorize requests using the `X-Hub-Signature-256` header. If the signature specified in
+    /// that header is not signed using the `webhook_secret` secret, the request will fail.
     pub fn new(webhook_secret: Secret) -> Self {
         Self { webhook_secret }
     }

src/service.rs

@@ -6,6 +6,7 @@ use sha2::Sha256;
 use std::task::{Context, Poll};
 use tower::Service;
 
+/// Middleware that authorizes all requests using the X-Hub-Signature-256 header.
 #[derive(Clone)]
 pub struct ValidateGitHubWebhook<S> {
     inner: S,