📝 Background image placeholder and instructions

Updated readme with instructions to mount the /public folder instead of the /public/icons folder, as well as added a placeholder for background image settings

src/components/Settings/AdvancedSettings.tsx

@@ -43,7 +43,11 @@ export default function TitleChanger() {
             placeholder="/favicon.svg"
             {...form.getInputProps('favicon')}
           />
-          <TextInput label="Background" placeholder="" {...form.getInputProps('background')} />
+          <TextInput
+            label="Background"
+            placeholder="/background.png"
+            {...form.getInputProps('background')}
+          />
           <Button type="submit">Save</Button>
         </Group>
       </form>