添加了首页的雏形，和一个关于如何添加页面的文档

gui/page/spkpagebase.cpp

@@ -1,6 +1,29 @@
 
 #include "page/spkpagebase.h"
 
+/*
+ * Documentation on
+ * How to Add a New Page to Main Window Side Bar
+ *
+ * 1. Derive your page widget class from SpkPageBase (reference implementation
+ *    in SpkPageSettings) and add them to CMakeLists
+ *
+ * 2. Add the ID for the page in enum SpkUi::SpkStackedPages (in spkmainwindow.h)
+ *    and add it as a resource context if needed
+ *
+ * 3. Include the page's header file in spkmainwindow.h and add a pointer to it in
+ *    SpkUi::SpkMainWidget
+ *
+ * 4. Add a tree item or icon button for the corresponding page inside
+ *    SpkUi::SpkMainWidget, and initialize it in SpkUi::SpkMainWidget::SpkMainWidget.
+ *    Take references of existing entries, and write similar code close to each other
+ *    to make the source look nice. Don't forget to add the item to the UI.
+ *
+ * 5. Make the linkage between the page and the sidebar item at the end of
+ *    SpkUi::SpkMainWidget::SpkMainWidget().
+ *
+ */
+
 SpkPageBase::SpkPageBase(QWidget *parent) : QWidget(parent)
 {