Docs section for developers

[stavros11]

Maybe we will need a different strategy for this as well, to avoid the usage of private elements.

An option could be even to retain this as it is, because we're allowing drivers only inside Qibolab (at least for the time being), but move it to a different section, because it is then info for the Qibolab developer, rather than for the Qibolab user.

Originally posted by @alecandido in #1053 (comment)