[Glitch] Add "Show thread" button to public profiles

Port 50cd73e5d7 to glitch-soc

Signed-off-by: Thibaut Girka <thib@sitedethib.com>

app/javascript/flavours/glitch/styles/statuses.scss

@@ -222,3 +222,20 @@
     }
   }
 }
+
+.status__content__read-more-button {
+  display: block;
+  font-size: 15px;
+  line-height: 20px;
+  color: lighten($ui-highlight-color, 8%);
+  border: 0;
+  background: transparent;
+  padding: 0;
+  padding-top: 8px;
+  text-decoration: none;
+
+  &:hover,
+  &:active {
+    text-decoration: underline;
+  }
+}