Source attributes in output template (#45)

* Updated download options to take a media item; allowed for specifying custom output path template options

* Fixed bug where indexing job wouldn't run for the first time

* Renamed friendly_name to custom_name

* Added new options to default template and UI

* Improved explainer UI

lib/pinchflat_web/controllers/sources/source_html/index.html.heex

@@ -14,7 +14,7 @@
     <div class="flex flex-col gap-10 min-w-max">
       <.table rows={@sources} table_class="text-black dark:text-white">
         <:col :let={source} label="Name">
-          <%= source.friendly_name || source.collection_name %>
+          <%= source.custom_name || source.collection_name %>
         </:col>
         <:col :let={source} label="Type"><%= source.collection_type %></:col>
         <:col :let={source} label="Should Download?">