message: guide: Document OpenSSL pre-requisite
  The build fails if OpenSSL development files cannot be located by
  the build script of openssl-sys. Document an OpenSSL Installation as a
  prerequisite in the Hermes guide.
diff: @@ -38,6 +38,11 @@ You will also need the __Go__ programming language installed and configured on y
  To install and configure Golang on your machine please follow the [Golang official documentation](https://golang.org/doc/install).
  +## 3. Libraries
  +
  +The OpenSSL library with its headers is required. Refer to the
  +[openssl crate documentation](https://docs.rs/openssl) for the ways to install OpenSSL on different platforms and make it available to the build script if necessary.
  +
  ## Next Steps
  Next, go to the [Installation](./installation.md) section to learn how to build Hermes.
  