Exhaustive documentation for package `configio`

[GregoryAlbouy]

Description

We want an exhaustive documentation for package configio.

It should be done once its API is stabilised, after the merge of the following:

• https://github.com/benchttp/engine/pull/58
• https://github.com/benchttp/engine/pull/62
• https://github.com/benchttp/engine/pull/59
• https://github.com/benchttp/engine/pull/61

Tasks

Once the above PRs are merged, add in configio:

• documenting comments for all exposed declarations
• go doc examples for main use-cases
• a readme at the package level

Suggestions

Notes