feat(smarttime.units): Add function to get human-readable time ago string from milliseconds.

ts/smarttime.units.ts

@@ -67,3 +67,7 @@ export let getMilliSecondsFromUnits = (combinationArg: IUnitCombinationArg) => {
 export const getMilliSecondsAsHumanReadableString = (milliSecondsArg: number): string => {
   return plugins.prettyMs(milliSecondsArg);
 };
+
+export const getMilliSecondsAsHumanReadableAgoTime = (timeStampArg: number): string => {
+  return plugins.dateFns.formatDistanceToNow(timeStampArg);
+}