Use Iconify icons for instructions

aleksis/apps/alsijil/templates/alsijil/instruction/list.html

@@ -63,7 +63,7 @@
       <div class=" col s12 m12 l6 xl4">
         <div class="card">
           <div class="card-content">
-            <i class="material-icons materialize-circle primary-color-text left small">{{ instruction.icon|default:"rule" }}</i>
+            <i class="material-icons materialize-circle primary-color-text left small iconify" data-icon="mdi:{{ instruction.icon|default:"clipboard-check-outline" }}"></i>
             <span class="card-title"> {{ instruction.name }}</span>
             {% has_perm "alsijil.edit_instruction_rule" user as can_edit %}
             {% has_perm "alsijil.delete_instruction_rule" user as can_delete %}

aleksis/apps/alsijil/templates/alsijil/partials/lesson/tabs/documentation.html

@@ -25,7 +25,7 @@
         <div class="collection">
           {% for instruction in instructions %}
             <div class="collection-item">
-              <i class="material-icons  primary-color-text left">{{ instruction.icon|default:"rule" }}</i>
+              <i class="material-icons  primary-color-text left iconify" data-icon="mdi:{{ instruction.icon|default:"clipboard-check-outline" }}"></i>
               <a href="{{ instruction.pdf_file.url }}" target="_blank">{{ instruction.name }}</a>
               <div class="right grey-text darken-4">
                 {% trans "Instruction done" %}&nbsp;&nbsp;
@@ -74,7 +74,7 @@
         <div class="collection">
           {% for instruction in lesson_documentation.done_instructions.all %}
             <div class="collection-item">
-              <i class="material-icons primary-color-text left">{{ instruction.icon|default:"rule" }}</i>
+              <i class="material-icons primary-color-text left iconify" data-icon="mdi:{{ instruction.icon|default:"clipboard-check-outline" }}"></i>
               <a href="{{ instruction.pdf_file.url }}" target="_blank">{{ instruction.name }}</a>
               <div class="right green-text">
                 <i class="material-icons left">check</i>