Changes

Experimental support for sparse dataframes
 (commit: 07a7612)

Use a slightly optimized simpler FeatureGenerator per default.
 (commit: d6494e8)

Make FeatureGenerator a dataclass to avoid redundant __init__.
 (commit: d2d73dc)

Fixed issue in TableDocumentDescriber
 (commit: 8d71481)

fix(corpus): parallel parsing
 (commit: 3a23d14)

fix(corpus): register corpus attributes.

When a Corpus would contain a token that is identical to one of the
attribute names (e.g., 'logger'), pandas would store the value assigned to
the attribute in (all rows of) the column of the underlying DataFrame.
 (commit: 35b0614)