docs: add a man page for the pmjson(1) utililty
docs: add a man page for the pmjson(1) utililty

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp