Added Changelog

[jnuernberg]

This is not really an issue, so please close, when read!

Hi everyone, Hi @awickert,

I took the liberty and added a changlog to the master branch to keep track of changes, additions, etc, that go into future versions. With more people contributing, I hope to keep track of more recent changes.

The structure is rather simple: The changelog consists of a list of sections, one per version, latest first. Above the latest version section, there is a section for the next, upcoming version. Whenever there is an addition of a feature or a change in code (either through direct edits or through PRs), add the changes as a bullet point to the upcoming versions sections.

When ready for the next version, change the upcoming version section to the next build-version and introduce a new upcoming version.

Final note on the bullet points: Be precise and comprehensive, just like in your commit messages.

Best regards,
Jacob

[IowaDave]

@awickert , @jnuernberg ,I am noticing a potential user-facing problem now that we have multiple people committing revisions. The version a user downloads with the Arduino IDE Library Manager becomes out of date. It appears we need to do additional steps after we merge a PR and enter a note in the Changelog?