Ffmpeg-normalize

* Add colorama to requirements, fixes 131.

* Fix warning that is printed with default options.

* Fix issue with output folder, fixes 126.

* Fix typo in README's table of contents link to "File Input/Output". (124)

* Clarify readme, fixes 122.

* Add warning for automatic sample rate conversion, addresses 122.

* Ignore vscode folder.

* Fix printing of errors in conversion.

* Fix unit tests.

* Improve handling of output file folder and errors.

* Clarify usage of output options, add warning.

* Improve documentation, fixes 120.

* Do not include bump messages in changelog.

* Use measured offset in second pass, fixes 119.

* Update release instructions.

* Remove author names from changelog.

* Update release script and changelog template.

* Apply pre-filters in all first passes, fixes 118.

This allows properly reading the level for any kind of normalization, even if
filters affect the loudness in the first pass.