style: add a comment explaining why we parse and build question separ…

…ately

src/editors/containers/ProblemEditor/data/OLXParser.js

@@ -307,6 +307,14 @@ export class OLXParser {
       return _.map(questionObject, (obj) => _.mapKeys(obj, (value, key) => _.get(tagMap, key, key)));
     };
 
+    // To be able to generate question's HTML, such that it respects the initial
+    // order of elements and styles stored in the OLX, we parse and build
+    // original `olxString` with `preserveOrder: true`. We parse and build the
+    // question separately, because the JSON structure produced with
+    // `preserveOrder: true` option is more complex and hard to work with, and
+    // since the order of nested elements is not important in other places, we
+    // restrict the complexity of the produced JSON within the scope of this
+    // method.
     const parser = new XMLParser({
       preserveOrder: true,
       trimValues: false,