tread 0.4.0

• Add tecan_unite() for stitching together time series measurements when the plate reader programme was stopped and restarted
• Add tecan_single_time_single_reads() and tecan_time_series_single_reads(), which allow tecan_parse() to deal with all four data formats (all combinations of single or multiple reads per well as well as single timepoint or time series)
• tecan_parse() now returns a tibble::tibble() with clean column names and correct column types
• Deprecated tecan_read_temperature() since it is a special case of tecan_parse() and much less flexible in regards to the format of the input file
• Improve documentation and create pkgdown website
• Expand unit testing and use GitHub CI