fixed y-axis for per-million chart value mode

covid.js

@@ -1125,13 +1125,24 @@ let updateChartSettings = () => {
     
     // move the y-axis zero point depending on whether we're showing cumulative or new cases
     if (document.querySelector('input[type=radio][name=chart-cases]:checked').value === 'cumulative') {
-        theChart.options.scales.yAxes[0].ticks.min = chart_start
+        if (document.querySelector('input[type=radio][name=chart-values]:checked').value === 'absolute') {
+            theChart.options.scales.yAxes[0].ticks.min = chart_start
+        } else {
+            theChart.options.scales.yAxes[0].ticks.min = 1
+        }
         theChart.options.scales.yAxes[0].scaleLabel.labelString = "Confirmed cases, cumulative"
     } else {
         theChart.options.scales.yAxes[0].ticks.min = 1
         theChart.options.scales.yAxes[0].scaleLabel.labelString = "Confirmed cases, new"
     }
     
+    // amend the y-axis label
+    if (document.querySelector('input[type=radio][name=chart-values]:checked').value === 'absolute') {
+        theChart.options.scales.yAxes[0].scaleLabel.labelString += ', absolute'
+    } else {
+        theChart.options.scales.yAxes[0].scaleLabel.labelString += ', per 1 million people'
+    }
+    
     // update x axis label
     if (chart_start == 1) {
         theChart.options.scales.xAxes[0].scaleLabel.labelString = "Days since 1st confirmed case"