Problem: Confirmation buffer is named with `nvim-pack://` as scheme
prefix and uses buffer id (needed for in-process LSP) as one an entry
in the "hierarchical part".
Solution: Use `nvim://pack-confirm#<buf>` format with a more ubiquitous
`nvim://` prefix and buffer id at the end as the optional fragment.
- Problem: It's not clear for new plugin developers that `:help` uses
a help-tags file for searching the docs, generated by `:helptags`.
- Solution: Hint to the |:helptags| docs for regenerating the tags
file for their freshly written documentation.
Co-authored-by: Yochem van Rosmalen <git@yochem.nl>
