wasm-smith: link design doc (#290)

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crates/wasm-smith/src/lib.rs

@@ -47,6 +47,11 @@
 //! > target](https://github.com/fitzgen/wasm-smith/blob/main/fuzz/fuzz_targets/validate.rs)
 //! > defined in this repository. Using the `wasmparser` crate, it checks that
 //! > every module generated by `wasm-smith` validates successfully.
+//!
+//! ## Design
+//!
+//! The design and implementation strategy of wasm-smith is outlined in
+//! [this article](https://fitzgeraldnick.com/2020/08/24/writing-a-test-case-generator.html).
 
 #![deny(missing_docs, missing_debug_implementations)]
 // Needed for the `instructions!` macro in `src/code_builder.rs`.