[FEATURE] free -h switch request.

[cederom]

Is your feature request related to a problem? Please describe.

• free is built in utility that shows memory usage.

• On platforms with large amounts of memory result of free is hard to read, for instance on rPI4B:

  nsh> free
        total       used       free    maxused    maxfree  nused  nfree name
  18446744073637310464      2279218446744073637287672      2346418446744073637287672     28      1 Umem
  

Describe the solution you'd like

Common approach in Unix / POSIX [1] utilities is to use -h switch to produce "human readable" output, for instance df [2]:

-h
The human-readable option selects to format sizes in metric units (e.g. 10 MB). Available in the BSD and GNU coreutils.

[1] https://en.wikipedia.org/wiki/List_of_POSIX_commands
[2] https://en.wikipedia.org/wiki/Df_(Unix)

Describe alternatives you've considered

No response

Verification

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