docs: add initial ADR on external tooling

[Frikki]

This PR is intended for receiving comments and suggestions. We could easily merge it, though not complete, as the document would just live as a proposal and can be updated to its development accordingly, leaving an excellent track record in Git.

Signed-off-by: Frederik Krautwald [email protected]

[briancavalier]

@Frikki Any idea why Travis is failing in this way?

36.23s$ npm install 
npm ERR! code ETARGET
npm ERR! notarget No matching version found for conventional-changelog-preset-loader@^1.1.3
npm ERR! notarget In most cases you or one of your dependencies are requesting
npm ERR! notarget a package version that doesn't exist.
npm ERR! notarget 
npm ERR! notarget It was specified as a dependency of 'conventional-changelog'
npm ERR! notarget 
npm ERR! A complete log of this run can be found in:
npm ERR!     /home/travis/.npm/_logs/2018-02-13T17_44_07_634Z-debug.log

I can't see how this branch would have introduced that problem, and master seems fine.

[briancavalier]

Weird, I wonder if it was a spurious issue. I re-ran the Travis build and it succeeded. 🤷‍♂️