Add Readme example to example_test.go (#298)

* Add speech to text example in docs

* Add caption formats for audio transcription

* Add caption example to README

* Address sanity check errors

* Add tests for decodeResponse

* Use typechecker for audio response format

* Decoding response refactors

* Migrated examples to example_test.go

* Add some executable examples

* Update error docs

* Avoid linting example files which break conventions

* Restore README examples

* Enable linting for example_test

examples/README.md

@@ -0,0 +1,6 @@
+To run an example:
+
+```
+export OPENAI_API_KEY="<your key here>"
+go run ./example/<target>
+```