feat(stats): show work and time-off lengths (#66)

src/i18n/en.json

@@ -140,8 +140,13 @@
 			"open": "Statistics",
 			"title": "Plan statistics",
 			"leaveDays": "New leave days",
+			"averageWorkSequence": "Average work sequence",
+			"averageTimeOffPeriod": "Average time-off period",
+			"longestTimeOffPeriod": "Longest time-off period",
+			"workingDays": "working days",
+			"calendarDays": "calendar days",
 			"partialPlan": "Partial plan",
-			"help": "Leave usage for the calculated plan. Already booked days are excluded."
+			"help": "Statistics for the calculated plan. Already booked days shape breaks and working stretches without consuming remaining balances."
 		},
 		"calculationDate": "Calculation date",
 		"futureEntitlement": "Future entitlement generated",