document environment variables

Author: jakobhellermann

README.md

@@ -36,3 +36,42 @@ INFO wasm_server_runner::server: starting webserver at http://127.0.0.1:1334
 ```
 
 The website will reload when the server is restarted and serve files relative to the current directory.
+
+## Configuration options
+
+All configuration options can be specified via environment variables.
+
+<details>
+<summary>WASM_SERVER_RUNNER_ADDRESS</summary>
+
+Default: `127.0.0.1`
+
+Control the address that the server listens on. Set to `0.0.0.0` to allow access from anywhere.
+
+</details>
+
+<details>
+<summary>WASM_SERVER_RUNNER_DIRECTORY</summary>
+
+Default: `.`
+
+Can be used to specify where relative path requests are loaded from.
+
+</details>
+
+<details>
+<summary>WASM_SERVER_RUNNER_HTTPS</summary>
+
+Default: `false`
+
+Controls whether https is used.
+
+</details>
+
+<details>
+<summary>WASM_SERVER_RUNNER_NO_MODULE</summary>
+
+Default: `false`
+
+Controls whether the wasm-bindgen output uses `module`s or not.
+</details>