Incomplete documentation for [[services.http_checks]] section

[DmitriyAlergant-T1A]

I found an issue with this document.

Title: App configuration (fly.toml)
Location: https://fly.io/docs/reference/configuration/
Source: https://github.com/superfly/docs/blob/main/reference/configuration.html.markerb

Describe the issue

The document provides example of the [[services.http_checks]] section, however it does not indicate where this section should be placed.

When placed at the top level of the fly.toml, which is most logical for those new to TOML, the http checks goes against port 8080, ignoring any custom internal port that may have been configured under the[[http_service]] section. I discovered that in order to go against the correct port, the [[services.http_checks]] needs to be placed under the [[services]] section that has defined the internal port.

This is an opportunity to improve the documentation.