`g:zettel_link_following` can be set to `cursor` or `line` to change the
way zk detect the closest link to follow to (or create a new link for).
Setting it to `cursor` will look for the current word under the cursor and
decide if it is a followable link. `line` will look from the current
cursor position to the end of the line instead.
Function takes an anchor (and optional link text and formatting style)
and transforms the input into a link to an anchor id.
Currently works for markdown and wikilink style link transforms.
Options were previously set ad-hoc in the initialize function, but
re-set and overwritten at various places.
Options now live in one central module (options.lua), where they
directly access the neovim options set, and re-access them on any run.
That means options can be changed while the plugin is running and it
will use their newer versions, without requiring any re-initialization.