[Feature Request] add column layout

[shitou333111]

Some cloud notes editor provide multi-column layout (picture below shows the 2-column example). It's very useful for picture with text on its left or right, because usually a picture can not take entire row width. This is a little bit different from table, it has no border, beautiful margin and adjustable ratio by drag the seperate line, each "cell" can contain other kinds of blocks, and usually has multi-column choice. If so, we can have the horizontal layout now.

[bolavefasfas]

+1

[i-iooi-i]

+1