Allow arbitrary HTTP headers to be added to requests

[kofron]

Adds a single function, with_additional_headers/1 that adds whatever heads the caller wants to the base request.

This is useful for e.g. using portkey's LLM gateway.

[restlessronin]

@kofron Have you tested this against portkey?

It might be a little more expressive for the additional headers to be a key-value map, rather than a header string.

I think we should also have an example in the user guide showing the exact call for the portkey sample.

You'll also have to run 'mix format' for the CI tests to pass.

[kofron]

@kofron Have you tested this against portkey?

Sure have! Works a charm.

It might be a little more expressive for the additional headers to be a key-value map, rather than a header string.

I like this suggestion, done.

I think we should also have an example in the user guide showing the exact call for the portkey sample.

Sounds good, happy to do that - how does one update the user guide. FWIW, it looks like this:

OpenaiEx.new(open_ai_api_key) 
|> OpenaiEx.with_base_url("https://api.portkey.ai/v1") 
|> OpenaiEx.with_additional_headers(%{"x-portkey-api-key"=>portkey_api_key, "x-portkey-provider"=>"openai"})

You'll also have to run 'mix format' for the CI tests to pass.

Done.

[restlessronin]

@kofron Looks good. The user guide is a livebook, so all the examples are executable. This probably belongs as a new subsection in the "Configuration" section between subsections "Base Url" and "Azure OpenAI".

If you could delete the @spec line (since we're not using those ATM), and add the doc to the user guide, we're good to go.

[kofron]

@restlessronin should be all set

[restlessronin]

@kofron Merged. Thanks much 🙏🏾🙏🏾 for the PR.

[kofron]

@restlessronin awesome, thanks for the library!

What's the release cycle like for this hitting hex.pm?

[restlessronin]

@kofron I just published v0.8.4 on hex.pm with the latest changes.