v2.0

This is the first formal release, even if previous versions were of course quite usable.
Versions before this git repo were informally v0.x
Versions up this release were informally v1.x

New highlights for this version are:

• feat: added a bunch of new --show-* options, along with --bright and --wide
• feat: view deleted parents of snapshots with --deleted and fix tree display when snapshots are orphaned (#7)
• feat: autodetect column size on display
• feat: when given mountpoint is not one, find its parent
• feat: add --btrfs-binary to specify a custom btrfs binary
• enh: better display in multi-filesystems mode
• a bunch of other tiny fixes/adjustments

Additionally, all released versions of btrfs from v3.18 to v5.15.1 have been tested and are confirmed to work.