add feed back option in about page

app/src/main/java/org/houxg/leamonax/ui/AboutActivity.java

@@ -83,4 +83,9 @@ public class AboutActivity extends BaseActivity {
         OpenUtils.openUrl(this, "https://github.com/houxg/Leamonax");
     }
 
+    @OnClick(R.id.ll_feedback)
+    void clickedFeedback() {
+        OpenUtils.openUrl(this, "https://github.com/houxg/Leamonax/issues");
+    }
+
 }

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

@@ -120,6 +120,21 @@
 
             <include layout="@layout/divider" />
 
+            <LinearLayout
+                android:id="@+id/ll_feedback"
+                style="@style/SettingsPanel"
+                android:orientation="vertical">
+
+                <TextView
+                    style="@style/SettingsSecondaryText"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:text="@string/feedback" />
+
+            </LinearLayout>
+
+            <include layout="@layout/divider" />
+
             <LinearLayout
                 android:id="@+id/ll_debug"
                 android:layout_width="match_parent"

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

@@ -73,4 +73,5 @@
     <string name="version">版本</string>
     <string name="yes">是</string>
     <string name="about">关于</string>
+    <string name="feedback">反馈</string>
 </resources>

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

@@ -72,4 +72,5 @@
     <string name="parse_error">Parse error</string>
     <string name="parsing_html">Parsing HTML</string>
     <string name="select_notebook">Select notebook</string>
+    <string name="feedback">Feedback</string>
 </resources>