Update toc should not change the undotree

[wsdjeg]

When use this plugin to edit a md file, after saving file, the toc is updated, but when I type u the cursor move to the toc menu, I think the undotree of current file is been updated.

[wsdjeg]

Maybe we should use :undojoin command, I will look into it to see if I can send a PR.

[mzlogin]

Yes, that's a problem. We should not change the undolist when there is no toc change.

I'll look into it. And, welcome to PR for this.

[wsdjeg]

I got another issue with this plugin, after save markdown file, `` in normal mode does not work, we can not jump to the position when last jump, but will jump to the beginning of TOC, I think it is due to how this plugin works.

I will look into this plugin, and I will fix it before SpaceVim/SpaceVim#806 is merged.

in this PR I will update SpaceVim's markdown layer.

[mzlogin]

Yes, I reproduce it. Maybe we can get help from keepjumps. Thanks for your work.