Switched out manual BIGNUMBER creation for the lua inbuilt `math.huge`.
Refactored `open_selected` a tiny bit in preparation for automatic link
creation.
Opens zettel by linked value, most often a direct path link, but will
also look through the root dir to find a(n exactly) matching basename to
open.
If nothing is found in the root dir will open a new file to write with
the corresponding name. Careful, if the reference is a full path
definition, and the file does not exist, it will still open the
corresponding file at the correct location but when attempting to save
will generally complain if parts of the path are missing. They have to
be created manually or in some other place, this is outside the scope of
this plugin.
`anchor.extract(string, anchor)` will find and extract a zettel anchor
from any string passed in.
It can be given an optional anchor regex which will supersede any regex
set in the plugin options.
By choosing 'line' in the `zettel_link_following` option, the link to be
opened will be searched for on the complete rest of the line, meaning
from the cursor to the newline symbol onwards.
`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.
