add some strings and formatting

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

@@ -17,6 +17,7 @@
     <string name="settings">Einstellungen</string>
     <string name="dark_theme">Dunkles Design</string>
     <string name="clear">Leeren</string>
+    <string name="change_background">Change background</string>
 
     <!-- About -->
     <string name="about">Über</string>

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

@@ -17,6 +17,7 @@
     <string name="settings">Impostazioni</string>
     <string name="dark_theme">Tema scuro</string>
     <string name="clear">Clear</string>
+    <string name="change_background">Change background</string>
 
     <!-- About -->
     <string name="about">Informazioni</string>

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

@@ -17,6 +17,7 @@
     <string name="settings">設定</string>
     <string name="dark_theme">ダークテーマ</string>
     <string name="clear">クリア</string>
+    <string name="change_background">Change background</string>
 
     <!-- About -->
     <string name="about">アプリについて</string>

app/src/main/res/values-pt-rPT/strings.xml

@@ -17,6 +17,7 @@
     <string name="settings">Definições</string>
     <string name="dark_theme">Tema escuro</string>
     <string name="clear">Limpar</string>
+    <string name="change_background">Change background</string>
 
     <!-- About -->
     <string name="about">Acerca</string>

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

@@ -17,6 +17,7 @@
     <string name="settings">Inställningar</string>
     <string name="dark_theme">Mörkt tema</string>
     <string name="clear">Clear</string>
+    <string name="change_background">Change background</string>
 
     <!-- About -->
     <string name="about">Om</string>