adding gitbook link and editor credits
adding gitbook link and editor credits

raazesh-sainudiin/scalable-data-science,raazesh-sainudiin/scalable-data-science,lamastex/scalable-data-science,raazesh-sainudiin/scalable-data-science,raazesh-sainudiin/scalable-data-science,lamastex/scalable-data-science,lamastex/scalable-data-science,lamastex/scalable-data-science,lamastex/scalable-data-science,lamastex/scalable-data-science