Added experimental settings with a custom timeout setting.

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

@@ -166,4 +166,6 @@
     <string name="new_items_notification_text">%1$d new items loaded.</string>
     <string name="pref_switch_notify_new_items">Notify on new items synced.</string>
     <string name="shortcut_offline">Offline</string>
+    <string name="pref_api_timeout">Api Timeout</string>
+    <string name="pref_header_experimental">Experimental</string>
 </resources>

app/src/main/res/xml/pref_experimental.xml

@@ -0,0 +1,9 @@
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
+    <EditTextPreference
+        android:inputType="number"
+        android:key="api_timeout"
+        android:selectAllOnFocus="true"
+        android:singleLine="true"
+        android:title="@string/pref_api_timeout" />
+
+</PreferenceScreen>

app/src/main/res/xml/pref_headers.xml

@@ -32,4 +32,9 @@
         android:icon="@drawable/ic_info_black_24"
         android:title="@string/pref_header_links"/>
 
+    <header
+        android:fragment="apps.amine.bou.readerforselfoss.settings.SettingsActivity$ExperimentalPreferenceFragment"
+        android:icon="@drawable/ic_action_lab"
+        android:title="@string/pref_header_experimental"/>
+
 </preference-headers>