Updating C API documentation to reflect client involvement in freeing RRCDataPtr instances

I have updated the documentation in the comment section (and will update the documentation on the website once the previous RRCDataPtr changes are released) to indicate to readers that the client is responsible for freeing the RRCDataPtr.

I also made typos and had errors trying to pull the changes onto my local repo, and it took about 3 commits with mistakes for me to iron that out.