docs(chatgpt): add section on other providers

[LoneRifle]

Short Description

Add a section after Integration Options, describing support for other LLM providers that provide OpenAI-compatible endpoints, including practical reasons for doing so.

Correct a typo while we're here.

Follows up on OpenFn/adaptors#1763

Details

The section has been added to highlight to the reader that the adaptor can be used in tandem with other LLMs and/or LLM providers.

This may be particularly useful for a variety of use cases relevant to OpenFn and its userbase, including:

• Using providers offering alternative LLMs and different pricing models
• Using self-managed inference services, such as vLLM or Ollama
• Using LLMs that cater to specific regions, such as SEA-LION from @aisingapore, which caters to South-East Asia

AI Usage

Please disclose how you've used AI in this work (it's cool, we just want to know!):

• I have used another model - meituan/longcat-2.0-free

You can read more details in our
Responsible AI Policy

Details

LongCat 2.0 was used to generate an initial draft. The version presented here has been heavily edited to fit the flow of the overall documentation.

[LoneRifle]

Hey @josephjclark - would you be kind enough to have a look at this PR please? This would make the recent change I did to the chatgpt adaptor visible. Thanks =)

If you also think I should put in similar documentation that would surface the change to the claude adaptor (less impact, since only Ollama and DeepSeek are the two major alternate Claude Messages API providers), please let me know!