[Feature] universal fzf: use one command to `fzf` sources of many different categories

[Song-Tianxiang]

When I use fzf, before I pressing the command, I always need to think about what I am search for. The thing I am searching for belongs to files, buffers, colorscheme, lsp symbols, tags, or other categories. This process was very interrupting to me. I think we can have a ctrl-p. It is a single command that can return all buffers, files, tags, or whatever I want. so that when we want fzf, we only need to press that command without thinking. fzf is fast and we can use this.

To do this, we need to build action preview and other things dynamicly, can we achieve it?

[junegunn]

It is possible, but it's a lot of work.