Notes: Add .underline for underlined text

Kinda resolves #499 but in a different way

Web/Models/Entities/Note.php

@@ -48,6 +48,7 @@ class Note extends Postable
             "acronym",
             "blockquote",
             "cite",
+            "span",
         ]);
         $config->set("HTML.AllowedAttributes", [
             "table.summary",
@@ -59,6 +60,8 @@ class Note extends Postable
             "img.style",
             "div.style",
             "div.title",
+            "span.class",
+            "p.class",
         ]);
         $config->set("CSS.AllowedProperties", [
             "float",
@@ -68,6 +71,9 @@ class Note extends Postable
             "max-width",
             "font-weight",
         ]);
+        $config->set("Attr.AllowedClasses", [
+            "underline",
+        ]);
         
         $purifier = new HTMLPurifier($config);
         return $purifier->purify($this->getRecord()->source);

Web/Presenters/templates/Notes/List.xml

@@ -54,6 +54,10 @@
         #userContent cite::before {
             content: "— ";
         }
+
+        #userContent .underline {
+            text-decoration: underline;
+        }
     </style>
 
     <div class="container_gray" style="background: white; border-top: none;">

Web/Presenters/templates/Notes/View.xml

@@ -33,6 +33,10 @@
         #userContent cite::before {
             content: "— ";
         }
+
+        #userContent .underline {
+            text-decoration: underline;
+        }
     </style>
 
     <article id="userContent" style="margin: 10px 10px 0;">