Add a README

Author: Fingercomp

README.md

@@ -0,0 +1,28 @@
+# gh-hook-command
+Sets up a simple HTTP server. The only endpoint it serves is `POST /hook`. When
+a GitHub webhook is sent there, the request is validated, and the command
+specified in the configuration file is run.
+
+## Installation
+```
+$ cargo build --release
+$ target/release/gh-hook-command
+```
+
+## Configuration
+The path to the configuration file is set by the `GH_HOOK_CONFIG` environment
+variable. If it's unset, `./config.toml` is used instead. The file will be
+created if it doesn't exist.
+
+```toml
+# The webhook secret key.
+secret = "secret secret really secret"
+
+# Address to bind to.
+bind = "0.0.0.0:8000"
+
+# The command list.
+[commands]
+# This runs `cat /dev/stdin && echo ""' on the `push` event.
+push = 'cat /dev/stdin && echo ""'
+```