add back readme

modules/openapi-generator/src/main/resources/ocaml/readme.mustache

@@ -0,0 +1,35 @@
+# {{{projectName}}}
+{{#appDescription}}
+{{{appDescription}}}
+{{/appDescription}}
+
+This OCaml package is automatically generated by the [OpenAPI Generator](https://openapi-generator.tech) project:
+
+- API version: {{appVersion}}
+- Package version: {{packageVersion}}
+{{^hideGenerationTimestamp}}
+- Build date: {{generatedDate}}
+{{/hideGenerationTimestamp}}
+- Build package: {{generatorClass}}
+{{#infoUrl}}
+For more information, please visit [{{{infoUrl}}}]({{{infoUrl}}})
+{{/infoUrl}}
+
+## Requirements.
+
+OCaml 4.x
+
+## Installation
+
+Please run the following commands to build the package `{{{packageName}}}`:
+
+```sh
+opam install ppx_deriving_yojson cohttp ppx_deriving cohttp-lwt-unix
+eval $(opam env)
+dune build
+```
+
+## Getting Started
+
+TODO
+