check case sensitivity and document it in README.md

[qknight]

Check if the idata or rdata fields check for case. My guess is no, but there is also a case switch for the FS I need to check.

https://learn.microsoft.com/en-us/windows/wsl/case-sensitivity

[ ] check if case in path or filename has an effect
[ ] check if the case-sensitivity setting has an effect on the resolver
[ ] document this in the README.md