PR: 225692
Restore some of the ctype definitions from pre-CLDR data, namely 0xE000-0xF8FF private use area, and 0xFF00-0xFFF half- and fullwidth punctuation. This does not, of course, fix all of the missing character type definition, but should fix the reported problem before 12.0 is released while I'm looking for complete longer term solution.
While here, I have updated the README a bit as I was actually using what was written there :-) Can be dropped as unrelated change.