[Request] Provide code comments for new contributors

[RequestPrivacy]

Description

I know it's annoying to comment the code one writes as it seems pretty much obvious what's going on BUT I saw an increasing up-tick in new people on social media who want to understand the software they run or even want to contribute (I count myself to this group).

Although at the start no big PRs can be expected the effort and potentially future improvements by them shouldn't be neglected.

Proposed Action

A small and simple comment describing what the following lines of code do in the bigger picture (no step by step, just a rough idea how a code block fits into the great scheme of things) would speed up their understanding of the software tremendously. Ideally they should be able to understand what and where the software does something alone through reading the comments. At interfaces (whirlpool, electrs etc.) a short sentence about interacting with those will also be helpful.

As a bonus (I know - time is scarce) selecting issues which are easy to implement could be marked with the good first issue tag.

Note: this issue isn't meant as critic or accusation nor should it be viewed as laziness or the wish to be "served a golden plate".