fix comma spacing and extra comma at end of modules list

Author: FoamyGuy

_includes/download/board.html

@@ -160,8 +160,7 @@ <h3>CircuitPython {{ version.version }}</h3>
           {% else %}
           <a target="_blank" class="library-link" href="https://docs.circuitpython.org/en/latest/shared-bindings/{{ module_name }}">
           {% endif %}
-            {{ module_name }}
-          </a>{% if module_name != version.modules[version.modules.size - 1] %}, {% endif %}
+            {{ module_name }}</a>{% unless forloop.last %}, {% endunless %}
           {% endfor %}
         </span>
     </p>
@@ -172,8 +171,7 @@ <h3>CircuitPython {{ version.version }}</h3>
         <span class="download-modules {% if version.stable %}stable{% else %}unstable{% endif %}">
           {% for module_name in version.frozen_libraries %}
           <a target="_blank" class="library-link" href="https://docs.circuitpython.org/projects/{{ module_name | split: 'adafruit_' | last }}">
-            {{ module_name }}
-          </a>{% if module_name != version.frozen_libraries[version.frozen_libraries.size - 1] %}, {% endif %}
+            {{ module_name }}</a>{% unless forloop.last %}, {% endunless %}
           {% endfor %}
         </span>
     </p>