tails multiple files and outputs with prefixes wheater they exist or not.
why: tail -f
/ tail -F
multi file output is horrible and it doesn't handle all cases when files come and go
$ tailer test1 test2
test1: hello
test2: world
test1: again
custom prefixes
$ tailer test1:t1 test2:t2
t1: hello
t2: world
t1: agin
COPY --from=ghcr.io/matti/tailer /tailer /usr/local/bin