Update README.Release_Manager_Cookbook to be consistent with what has occurred for the 5.11.0 release
Update README.Release_Manager_Cookbook to be consistent with what has occurred for the 5.11.0 release

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot