[Add Features ] Support: page break, etc.

[Evilran]

[Add Features ] Support: page break, centered images, centered tables, etc.

• Support for HTML Pagination, fix Addin page breaks? #31
• Support for centering tables.
• Modified the way to insert images, supports the function of customizing the size and centering of the picture (I had encountered the problem of base64 pictures not being inserted), inspired by [erezlife/html2docx], links to <img src="data:image/png;base64,xxxx==> #12