docs: Add some notes about cdylib

Closes: #683

Author: ctron

site/content/_index.md

@@ -110,6 +110,23 @@ include all JavaScript snippets generated by `wasm-bindgen` for interfacing with
 By default, functions exported from Rust, using `wasm-bingen`, can be accessed in the JavaScript code through the global
 variable `window.wasmBindings`. This behavior can be disabled, and the name can be customized. 
 
+## Library crate
+
+Aside from having a `main` function, it is also possible to up your project as a `cdylib` project. In order to do that,
+add the following to your `Cargo.toml`:
+
+```toml
+[lib]
+crate-type = ["cdylib", "rlib"]
+```
+
+And then, define the entrypoint in your `lib.rs` like (does not need to be `async`):
+
+```rust
+#[wasm_bindgen(start)]
+pub async fn run() {}
+```
+
 # Next Steps
 
 That's not all! Trunk has even more useful features. Head on over to the following sections to learn more about how to use Trunk effectively.