Add page settings, improve settings UI

CHDataManagement/Preview Content/WebsiteData+Mock.swift

@@ -6,6 +6,7 @@ extension Settings {
         outputDirectoryPath: "/some/path",
         navigationBar: .init(iconPath: "/some/other/path", tags: []),
         posts: .mock,
+        pages: .mock,
         german: .german,
         english: .english)
 }
@@ -17,6 +18,13 @@ extension PostSettings {
     }
 }
 
+extension PageSettings {
+
+    static var mock: PageSettings {
+        .init(pageUrlPrefix: "pages", contentWidth: 600)
+    }
+}
+
 extension LocalizedSettings {
 
     static var german: LocalizedSettings {