This was incorrectly ported from Rust to Go.
When provided, `treefmt` will take the contents of stdin and place them into the file provided with the `--stdin` flag, then format it according to the configured formatters.
If the file doesn't exist it is created. If it exists, it is first truncated and then populated with stdin.
Signed-off-by: Brian McGee <brian@bmcgee.ie>
By default, if a path does not match any formatter a log message at WARN level will be emitted. A user can change this by providing the `--on-unmatched` or `-u` flag and specifying a log level `debug,info,warn,error,fatal`.
If fatal, the process will exit with an error on the first unmatched path encountered.
Closes#302
Signed-off-by: Brian McGee <brian@bmcgee.ie>
