truncate_input: Truncate climate and tree data to common interval
In cszang/treeclim: Numerical Calibration of Proxy-Climate Relationships

Truncate climate and tree data either to common shared interval (default) or to specified range of years. Depending on minmonth, the climate data will need to start one year earlier than the tree data, if data from the previous year should be used.

truncate_input(
  chrono,
  climate,
  timespan = NULL,
  minmonth,
  dynamic,
  silent = FALSE
)

`chrono`	a tree-ring chronology
`climate`	the climate data as returned by as_tcclimate
`timespan`	the timespan for truncating as vector with min and max year
`minmonth`	the earliest month used for the calibration, as returned by check_months
`moving`	moving or not? (logical)