Simple graph maker

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ver2.3.0
・Added support for save graphs in the local data
・You can now edit the graph by pressing the back key
・Fixed some bugs and issues

ver 2.2.0
・Changed the UI
・Changed the line chart design
・Improved the resolution of the graph
・Fixed a bug that sometimes can't see the graph
・Fixed some small bugs

ver 2.1.0
Added support for make a bar chart