Include fuzz testing setup (#274)

tests/h2-tests/README.md

@@ -5,3 +5,19 @@ crate because they transitively depend on the `unstable` feature flag via
 `h2-support`. Due to a cargo limitation, if these tests existed as part of the
 `h2` crate, it would require that `h2-support` be published to crates.io and
 force the `unstable` feature flag to always be on.
+
+## Setup
+
+Install honggfuzz for cargo:
+
+```rust
+cargo install honggfuzz
+```
+
+## Running
+
+From within this directory, run the following command:
+
+```
+HFUZZ_RUN_ARGS="-t 1" cargo hfuzz run h2-fuzz
+```