Change output to match the Linux version of free

[afbjorklund]

The units and white space are slightly different, but I wanted free and lima free to match...

So I changed the output to look like the Linux version, i.e. specifically the one from Ubuntu.

$ free -h
               total        used        free      cached         app       wired
Mem:          16.0Gi       8.8Gi       1.3Gi       5.8Gi       6.8Gi       1.1Gi
Swap:           0.0B        0.0B        0.0B
$ uname
Darwin
$ lima free -h
               total        used        free      shared  buff/cache   available
Mem:           3.8Gi       363Mi       2.9Gi       5.2Mi       679Mi       3.5Gi
Swap:             0B          0B          0B
$ lima uname
Linux

Hmm, perhaps the "0B" needs to be tweaked as well.

Then again, also missing -g and -m and -k et al...