Finished implementing a Solutions version for each exercise

src/demo/reading.json

@@ -5,11 +5,13 @@
   },
   "module": "reading",
   "minTimer": 5,
+  "id": "ffb738a5-265c-4daa-85c4-3681d3f8b48b",
   "exercises": [
     {
       "type": "fillBlanks",
       "prompt": "Complete the summary below. Click a blank to select the corresponding word for it.\nThere are more words than spaces so you will not use them all. You may use any of the words more than once.",
       "allowRepetition": true,
+      "id": "acf930d1-3615-4b7d-b057-9f6e60b30f74",
       "solutions": [
         {
           "id": "1",
@@ -71,6 +73,7 @@
     {
       "type": "matchSentences",
       "prompt": "Look at the following notes that have been made about the matches described in Reading Passage 1. Decide which type of match (A-H) corresponds with each description and write your answers in boxes 9 15 on your answer sheet.",
+      "id": "404437ff-2bc0-44b5-9e32-40ef4eedb023",
       "sentences": [
         {
           "id": "9",