Features
* Multi-instance player support. It's now possible to specify a player by its non-unique name prefix only, without the unique instance suffix, e.g., `-p firefox` instead of `-p firefox.instance_1_34`. The blocklet monitors all instances and pick the new one when the previous disappears.
* Improved formatter by [tellezhector](https://github.com/tellezhector):
- Added fallback to built-in `Formatter` format specs. See [Python Docs](https://docs.python.org/3.8/library/string.html#format-examples).
- Added a format_spec for truncating strings and adding a suffix `{string:.<max_length>,<suffix>}`.
* Added a placeholder message displayed when there is no player.
Changes
* The blocket no longer handles `SIGINT`. See [PR 14](https://github.com/un-def/i3blocks-mpris/pull/14) for an explanation.