add a USW link in the manager

_locales/en/messages.json

@@ -630,6 +630,10 @@
     "message": "Translate",
     "description": "Transifex link text on the manage page"
   },
+  "linkUSW": {
+    "message": "Upload and discover styles on userstyles.world",
+    "description": "Link text for https://userstyles.world/ on the manage page"
+  },
   "linterCSSLintIncompatible": {
     "message": "CSSLint doesn't support $preprocessorname$ preprocessor",
     "placeholders": {

manage.html

@@ -333,6 +333,9 @@
         <span><a href="https://add0n.com/stylus.html#features" target="_blank" i18n-text="linkGetHelp"></a></span>
         <span><a href="https://github.com/openstyles/stylus/wiki" target="_blank" i18n-text="linkStylusWiki"></a></span>
         <span><a href="https://www.transifex.com/github-7/Stylus" target="_blank" i18n-text="linkTranslate"></a></span>
+        <span><a href="https://userstyles.world/" target="_blank" i18n-text-append="linkUSW" id="link-usw">
+          <img src="https://userstyles.world/favicon.ico">
+        </a></span>
       </div>
     </div>
   </div>

manage/manage.css

@@ -440,6 +440,24 @@ a:hover {
   margin: 0 .5em;
 }
 
+#link-usw {
+  display: flex;
+  align-items: center;
+  margin-top: .5em;
+}
+
+#link-usw img {
+  max-width: 2.5em;
+  max-height: 2.5em;
+  margin-right: .75em;
+  filter: grayscale(1);
+  transition: filter .5s;
+}
+
+#link-usw:hover img {
+  filter: none;
+}
+
 .newUI .entry .svg-icon.checked,
 .newUI .entry:hover .svg-icon.checked {
   fill: #000;