1.4.0

• Adds support for Python 3.13, drops 3.7 & 3.8
• Added tutorial Jupyter notebook
• Added FlowData.as_array() method for retrieving events as a 2-D NumPy array with optional preprocessing event data for gain, log scaling, and time scaling (Adds NumPy dependency)
• Renamed FlowData arg filename_or_handle to fcs_file
• Added the following FlowData attributes:
  • version: FCS version of the imported file
  • data_type: type of data in DATA segment (ASCII, integer, floating point)
  • pnn_labels: list of names for parameters (required)
  • pns_labels: list of optional names for parameters
  • pnr_values: list of channel range values (required)
  • fluoro_indices: list of indices of fluorescent channels
  • scatter_indices: list of indices of scatter channels
  • time_index: index of the time channel
  • null_channels: list of channel indices not intended for analysis (omitted from fluoro_indices, scatter_indices, and time_index)
• Make fcs_keywords module public
• Reduce memory footprint when creating FCS files from events with type array (thanks to @christianrickert for PR #32)
• Support pathlib.Path when creating FlowData instances (thanks to @Zethson)
• Support empty "timestep" keyword values (thanks to @ikonsta for PR #33)