There's a new category "Swimming and Bathing" (under "Leisure, Sport and Shopping"). It includes a variety of swimming and bathing facilities:
- natural=water, sport=swimming
- amenity=public_bath (it will add the "bath:type" in the description)
- leisure=swimming_pool (only those, which don't have "access=private" set)
- leisure=sauna (it will add the "sauna:type" in the description)
I'm not too happy about the icons yet, also there might be other possible improvements (colors for different types of map features, other map features, ...). You may post ideas on the Github issues page.