Add automatically generated change log file.

[skywinder]

Hi, as I can see, you are carefully fill tags and labels for issues in your repo. I created a github_changelog_generator, that generate change log file based on tags, issues and merged pull requests (and split them to separate lists according labels) from GitHub issue tracker. This Change Log was automatically generated by this script. It helps to easily found what and when was fixed and implemented. You can easily update this file in future by running script: github_changelog_generator in your repo folder. Hope you find this commit as useful.

[groue]

Hi.

I won't merge this pull request, for the following reasons:

• This automatic change log is wrong: in the "Unreleased" section there are fixes that are, in fact, released.
• This automatic change log is misleading: there are links to issues that are not code related and have nothing to do with a change log: discussions, false issues, etc.
• This automatic change log will never fit the way GRMustache is developped. This library is not issue-driven, it is author-driven: I don't have to wait for users to open issues before I add features or fix bugs.
• This project already has release notes, and if you look at it, you'll see that your automatic change log does not quite fit the standards of a human-crafted one: https://github.com/groue/GRMustache/blob/master/RELEASE_NOTES.md

Now, one more thing. You've been submitting a lot of such PRs recently (https://github.com/skywinder?tab=activity), trying to push a work of questionable quality. The next time you bother me, I will report you as a spammer.

Have a nice day.