README.md: add something that could pass as documentation in some parallel universe that has really sloppy standards ;)
ringfs.c: use C99-compliant printf format
tests.c: keep functions static if possible
ringfs.h: add ringfs_capacity()
ringfs_scan: fix write head detection
add count & capacity + tests
ringfs.c: reorder functions to match header
add ringfs_count_estimate() + tests
flashsim: don't color output by default
add CHANGELOG.md
add example.c