Use custom html elements that have only the slot / solution id and replace...

Use custom html elements that have only the slot / solution id and replace them in UFrameIT with the actual data, because I can't fill in the data-fact-id from here without larger code chages.

source/Scrolls/TriangleScrolls.mmt

@@ -107,28 +107,28 @@ theory OppositeLen =
     <span>Given a triangle</span>
     <math>
         <mi>&xutri;<!-- △ --></mi>
-        <mi dropzone='copy' data-slot-id='http://mathhub.info/FrameIT/frameworld?TriangleProblem?A'>${lverb A}</mi>
-        <mi dropzone='copy' data-slot-id='http://mathhub.info/FrameIT/frameworld?TriangleProblem?B'>${lverb B}</mi>
-        <mi dropzone='copy' data-slot-id='http://mathhub.info/FrameIT/frameworld?TriangleProblem?C'>${lverb C}</mi>
+        <scroll-slot>http://mathhub.info/FrameIT/frameworld?TriangleProblem?A</scroll-slot>
+        <scroll-slot>http://mathhub.info/FrameIT/frameworld?TriangleProblem?B</scroll-slot>
+        <scroll-slot>http://mathhub.info/FrameIT/frameworld?TriangleProblem?C</scroll-slot>
     </math>
     <span>right-angled at</span>
     <math>
         <!--<mi>&angrtvbd;</mi>--><!-- ⦝ -->
-        <mi dropzone='copy' data-slot-id='http://mathhub.info/FrameIT/frameworld?TriangleProblem_RightAngleAtC?rightAngleC'>${lverb rightAngleC}</mi>
+        <scroll-slot>http://mathhub.info/FrameIT/frameworld?TriangleProblem_RightAngleAtC?rightAngleC</scroll-slot>
     </math>,<br />
     <span>the opposite side has length</span>
     <math>
-        <mi data-solution-id='http://mathhub.info/FrameIT/frameworld?OppositeLen/Solution?deducedLineCA'>${lverb deducedLineCA}</mi>
+        <scroll-solution>http://mathhub.info/FrameIT/frameworld?OppositeLen/Solution?deducedLineCA</scroll-solution>
         <mo>&equals;</mo>
         <mrow>
             <mi>tan</mi>
             <!--<mo>&#8289;</mo>-->
             <mo>(</mo>
-            <mi dropzone='copy' data-slot-id='http://mathhub.info/FrameIT/frameworld?TriangleProblem_AngleAtB?angleB'>${lverb angleB}</mi>
+            <scroll-slot>http://mathhub.info/FrameIT/frameworld?TriangleProblem_AngleAtB?angleB</scroll-slot>
             <mo>)</mo>
         </mrow>
         <mo>&#8290;</mo>
-        <mi dropzone='copy' data-slot-id='http://mathhub.info/FrameIT/frameworld?OppositeLen/Problem?distanceBC'>${lverb distanceBC}</mi>
+        <scroll-slot>http://mathhub.info/FrameIT/frameworld?OppositeLen/Problem?distanceBC</scroll-slot>
     </math>
     <span>.</span>
 </scroll-description>" ❙