Add ticks and labels to slider scale

Author: anchouls

ij-plugin/src/main/kotlin/org/jetbrains/research/tasktracker/config/survey/HtmlQuestion.kt

@@ -199,6 +199,17 @@ data class SliderHtmlQuestion(
         append("min=\"$min\" max=\"$max\" step=\"$step\" ${isRequiredString()} ")
         append(" style=\"width: 100%; display: block;\">")
 
+        append("<div style=\"display: flex; justify-content: space-between; color: white;\">")
+        (min..max step step).forEachIndexed { index, value ->
+            append("<div style=\"text-align: center; flex: 1; position: relative;\">")
+            append("<div style=\"width: 2px; height: 10px; background: white; margin: auto;\"></div>")
+            if (index % 5 == 0) {
+                append("<span style=\"display: block; margin-top: 2px;\">$value</span>")
+            }
+            append("</div>")
+        }
+        append("</div>")
+
         append("<div style=\"display: flex; justify-content: space-between; color: white;\">")
         append("<span>${labels.min}</span>")
         append("<span>${labels.max}</span>")