Documentation for "match" option not up to date, maybe add a warning

[claradaia]

Hello,
First of all thank you for the package, super helpful!

I downloaded it today with ssc install, then encountered a few issues while attempting to use the match option and ended up here.

I can see that the documentation for match was updated here 1295d28, but the info I needed ("can't be used with the indicators option") does not show in the help page when I open it through Stata. ado update says the package is up to date, so perhaps something else needs to be done to update the docs in the registry?

Also, before I knew match could not be used with the indicators option, I ran the command and was just puzzled by the dataset not having the indicators. I believe it might be good to throw an error or at least a warning if the user tries to use both. If you agree, I can attempt to implement it and PR.