ref: 2da1dde5ea566f82ebe6532bc6d3b8670fd77ce8 dotfiles/vim/.vim/after/ftplugin d---------
Update vim markdown settings

- Use 'commonmark' format with pandoc for formatprg
- Fix undo_ftplugin variable (forgot to change mapping)
- Remove custom syntax definitions that concealed links
- Update ft#markdown#open() regex pattern
Add mapping to open Markdown links in a split
Open links in Markdown files with Return
Don't set 'spell' automatically for markdown files
Remove latent vimwiki file
Update vim filetype plugins
Use tabs in go files (as per gofmt)
Variety of vim changes/improvements

- Add go ftplugin
- Fix bug in fzy#tags() function
- Ensure LSP command actually exists in ALE LSP buffers
- Update Scratch command to work with external commands
Add scdoc ftplugin
Refactor Markdown formatexpr function

- Rename to ft#markdown#formatexpr
- Use `:g` instead of `:s` to unwrap wrapped links
- Replace *italics* with _italics_
- Replace ``` {.lang} with ```lang for fenced code blocks
Vim tweaks

- Use simplified fork of base16-vim
- Simplify mail ftplugin and add (some) markdown syntax to mail buffers
- Decouple fugitive dependency for fzy git ls-files
- Set 'backup' and change 'breakat' settings
- Remove wildignore.vim plugin
Enable spell checking in mail files

Also disable highlighting trailing whitespace
Prune vim configuration

- Remove configurations for plugins no longer in use
- Remove a few custom "plugins" that don't get used much/ever
Don't highlight trailing whitespace in readonly buffers

Also don't start insert mode in mail files when they are readonly
Automatically place cursor when writing mail messages
Add Reflinks command to undo_ftplugin
Further tweaks to Markdown ftplugin

Use 'formatexpr' to "pre-filter" the file before running it through
'formatprg'. This escapes spaces in links in list items, to prevent

    -   [A link to a really cool article](https://reallylongurltoacoolarticle.biz/foo/bar/baz/omg/wow)

from becoming this:

    -   [A link to a really
        cool article](https://reallylongurltoacoolarticle.biz/foo/bar/baz/omg/wow)

Also switch back to using `markdown` format instead of `gfm` in pandoc
since it does work just a little bit better.

Also add a new buffer-local command `:Reflinks` that toggles using the
`--reference-links` option.
Update markdown ftplugin
Use pandoc as markdown formatter
Use 'q' to quit help buffers

This reverts a change in bd18a34e