Make commits conform to mkchlog format

[Kixunil]

This introduces mkchlog to the project so that the changelog could be auto-generated.

[apoelstra]

ACK 41aaf77

[apoelstra]

cc @tcharding could you take a look at this one since you've been more active in the rust-bitcoin equivalent?

[tcharding]

ACK 41aaf77

[tcharding]

Looks good, probably want to let @clarkmoody ack this though because introducing this requires devs to learn the new tool, took me about 15 mins to read the docs and play around with it.

Clark, the idea, if you are ok with it, would be to merge this PR and then #141

[tcharding]

I threw #151 on top of this branch locally and ran mkchlog gen, which led to crywolf/mkchlog#18

But I think we can still merge this and the fix will be ready by the time we do another release, @Kixunil do you agree?

[Kixunil]

@tcharding yes, output issues can be solved in parallel. Just checking is enough for now.

[clarkmoody]

Is there any documentation for this change? How would a new contributor know what to do?

[tcharding]

Oh good point, while I was playing around I wrote a whole bunch of docs in the README (I think it was in this repo) then deleted it all because it got too close to whats already in the mkchlog repo's README. We should definitely mention mkchlog and link it.

[tcharding]

Might be worth putting a decent effort into it here since we can then copy'n'paste to every other repo as we introduce mkchlog.

[Kixunil]

I was thinking of making a guide to (new) contributors that woul live directly in mkchlog repo and could be linked.

[tcharding]

The docs in the mkchlog readme are pretty good already. Just a few short well worded sentences and a link was all I had in mind.

[Kixunil]

They are geared towards maintainers ("why and how should you use this in your project"), not towards contributors ("what should you do to get your contribution in ASAP").

[tcharding]

Fair point

[clarkmoody]

What do we need to make progress on this?

[tcharding]

From my perspective this is good to go, mkchlog is so new I'm ok to deal with teething problems as we go, like explaining how to use it to any new contributor. Soon as better docs are available we will remember to link to them I rekon since we will hopefully be adopting this org wide. Just my 2 cents.

[tcharding]

What do we need to make progress on this?

An ACK from you I rekon @clarkmoody.

[tcharding]

Or were you waiting on docs improvements (in the mkchlog repo or here) @clarkmoody ?

[clarkmoody]

Or were you waiting on docs improvements (in the mkchlog repo or here) @clarkmoody ?

I would expect at least some note to contributors in the README with a link to external docs.