v2.0.3 - XLE 12 leads and format detection

ECGDataKit 2.0.3

• XLE (experimental): XLEParser(wilson_correction=True, compute_missing_leads=True) gives the standard 12 leads. III, aVR, aVL and aVF are computed from I and II, with a warning. The option requires the Wilson correction.
• New FileParser.detect_format(path): tells the format of a file and the parser that reads it, without parsing it.
• FileParser.parse(path) no longer needs an instance. FileParser().parse(path) still works.

Full Changelog: v2.0.2...v2.0.3