v0.22.0

Release 0.22.0

Improvements:
- Extend the set of time series and radial profiles known by StagPy to
  match what can be outputted by StagYY.
- Time series and rprof names now match the names outputted by StagYY.
  Previous names are still aliased by StagPy for convenience.

Bug fixes:
- The `+timelabel` option of the `field` command respects
  the configured scaling for time values.
- Time series with a varying number of columns during a run now works as
  expected, resulting in `NaN` values in the missing columns.