docs: fix usage page to match latest version's default adapter specification

[mi-wada]

Description

Since #1366, the default value for default_adapter is :net_http.

Additional Notes

The added Adapters section was referenced here.

[olleolleolle]

I like this, thank you!

As a follow-up, when looking at the Adapters page, I think as a reader, I would like a snippet of code in context, to take the mystery out of it. Setting a different default_adapter and so on.

https://lostisland.github.io/faraday/adapters/

@iMacTia Do you agree that something more concrete on that page could guide a half-knowledgeable reader to the water?

[mi-wada]

@olleolleolle

As a follow-up, when looking at the Adapters page, I think as a reader, I would like a snippet of code in context, to take the mystery out of it. Setting a different default_adapter and so on.

https://lostisland.github.io/faraday/adapters/

Sure looks better that way!

07f78ac

I have added a doc about this and would appreciate a review.

[iMacTia]

This looks great! Thank you for improving the doc @mi-wada and thanks @olleolleolle for the suggestion 🙏 !