The docs look good. Thanks for writing them!
I've got a couple of ideas for some minor improvements:
1) Reference manual: In the list of valid attribute values, I think it would be good to add one sentence explaining the typical meaning of the different strengths. For example:
- PRIMARY typically means that only differences in the base letter are considered significant, case and accents are not considered significant.
- SECONDARY typically means that case differences are not considered significant, whereas differences in base letters or accents are significant.
- TERTIARY typically means that differences in the base letter, accents or case are all considered significant.
- IDENTICAL means that all differences are considered significant.
2) tdevdvlpcollation: The "'a' with grave" part could be written as "'à' ('a' with grave)" for clarity. (The escape sequence for "à" is "à", if you would like to avoid non-ascii characters in the source file, although it should be fine to type the character directly and save as UTF-8, see the declaration of encoding in the header.)
Otherwise, the changes look great.