Improve accessibility

app/src/main/res/layout/settings_ignorelist.xml

@@ -37,6 +37,7 @@
     android:layout_height="wrap_content"
     android:layout_gravity="end|bottom"
     android:layout_margin="16dp"
+    android:contentDescription="@string/label_new_ignore_rule"
     app:fabSize="normal"
     app:srcCompat="@drawable/ic_add"
     app:tint="?colorTextPrimaryInverse" />

app/src/main/res/values/strings.xml

@@ -82,6 +82,7 @@
   <string name="label_new_highlight_ignore_rule">New Highlight Ignore Rule</string>
   <string name="label_new_highlight_rule">New Highlight Rule</string>
   <string name="label_new_identity">New Identity</string>
+  <string name="label_new_ignore_rule">New Ignore Rule</string>
   <string name="label_new_network">New Network</string>
   <string name="label_new_nick">New Nick</string>
   <string name="label_new_server">New Server</string>