feat: Parse date, lastmod and notes from LOGBOOK drawers

[kaushalmodi]

Fixes #203

• Fix run time error when parsing plist data only on Emacs 26.3 - https://lists.gnu.org/r/help-gnu-emacs/2022-05/msg00022.html -- The "fix" was actually a workaround to use alist instead of plist for the logbook entry.
• Export LOGBOOK notes to logbook.notes TOML Table array
• Interpret date from LOGBOOK state changes
• Interpret lastmod from LOGBOOK state changes
• Update ox-hugo manual with info on :LOGBOOK: drawer exports

Documentation

https://ox-hugo.scripter.co/doc/drawers/

Example usage

scripter.co commit # cae86abc

[kaushalmodi]

Spec

Org note heading settings

Assume that user has kept the default value of org-log-note-headings.

Parsing state changes

:LOGBOOK:
- State "DONE"       from "DRAFT"      [2018-09-06 Thu 11:25]
- State "DRAFT"      from "TODO"       [2018-09-06 Thu 11:25]
- State "TODO"       from              [2018-09-06 Thu 11:25]
:END:

Above exports to this in TOML front-matter:

date = 2018-09-06T11:25:00-04:00
draft = false

Parsing notes added to LOGBOOK drawers using C-c C-z

:LOGBOOK:
- Note taken on [2022-05-04 Wed 13:15] \\
  This new note added last should be the first element of the
  ~[[logbook.notes]]~ TOML table array.
- Note taken on [2022-04-08 Fri 14:53] \\
  This note addition prompt shows up on typing the ~C-c C-z~ binding.
  See [[info:org#Drawers]].
- Note taken on [2018-09-06 Thu 11:45] \\
  Another note *bold* /italics/.
- Note taken on [2018-09-06 Thu 11:37] \\
  A note ~mono~.
- State "DONE"       from "DRAFT"      [2018-09-06 Thu 11:25]
- State "DRAFT"      from "TODO"       [2018-09-06 Thu 11:25]
- State "TODO"       from              [2018-09-06 Thu 11:25]
:END:

Above exports to this in TOML front-matter:

[logbook]
  [logbook._toplevel]
    [[logbook._toplevel.notes]]
      timestamp = 2022-05-04T13:15:00+00:00
      note = """
  This new note added last should be the first element of the
  `[[logbook.notes]]` TOML table array.
  """
    [[logbook._toplevel.notes]]
      timestamp = 2022-04-08T14:53:00+00:00
      note = """
  This note addition prompt shows up on typing the `C-c C-z` binding.
  See [Org Info: Drawers](https://orgmode.org/manual/Drawers.html "Emacs Lisp: (info \\"(org) Drawers\\")").
  """
    [[logbook._toplevel.notes]]
      timestamp = 2018-09-06T11:45:00+00:00
      note = "Another note **bold** _italics_."
    [[logbook._toplevel.notes]]
      timestamp = 2018-09-06T11:37:00+00:00
      note = "A note `mono`."

Note:

1. The state change information does not get exported to the logbook. .. .notes table array.
2. ❗ YAML export will not be supported.

[kaushalmodi]

Improvements to this PR were added in #635.