fix: update word break style

hotfix: bug fix

fix: resolve resetting problem

修复重置问题

feat: add image upload format and size limitation

受公众号限制，上传图片的大小不能超过 5M

fix: update css2json and fix doocs#7

修复页面卡死问题(doocs#7)

feat: add one-click paste and upload image function

添加一键粘贴上传图片功能

feat: add one-click download function

新增一键下载功能

fix: update the width of image

更新图片展示宽度

style: fix custom css

修复样式错误

fix: remove images upload limitation

移除图片上传限制