[WIP] Use CommonDoc for intermediate documentation representation

[svetlyak40wt]

This way it will be easier to write custom documentation nodes, locatives and HTML themes.

             *     ,MMM8&&&.            *
                  MMMM88&&&&&    .
                 MMMM88&&&&&&&
     *           MMM88&&&&&&&&
                 MMM88&&&&&&&&
                 'MMM88&&&&&&'
                   'MMM8&&&'      *
          |\___/|
         =) ^Y^ (=            .              '
          \  ^  /
           )=*=(       *
          /     \
          |     |
         /| | | |\
         \| | |_|/\
  jgs_/\_//_// ___/\_/\_/\_/\_/\_/\_/\_/\_/\_
  |  |  |  | \_) |  |  |  |  |  |  |  |  |  |
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[coveralls]

Pull Request Test Coverage Report for Build 1157786278

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 1848 of 3325 (55.58%) changed or added relevant lines in 61 files are covered.
• 460 unchanged lines in 39 files lost coverage.
• Overall coverage increased (+2.2%) to 42.628%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/locatives/argument.lisp	0	1	0.0%
src/locatives/method.lisp	11	12	91.67%
src/markdown.lisp	0	1	0.0%
src/locatives.lisp	0	2	0.0%
src/locatives/restart.lisp	0	2	0.0%
src/locatives/section.lisp	2	4	50.0%
src/locatives/dislocated.lisp	0	3	0.0%
src/locatives/generic-function.lisp	11	14	78.57%
src/restart.lisp	0	3	0.0%
src/link.lisp	0	4	0.0%
<!--	Total:	1848	3325	55.58%	-->

Files with Coverage Reduction	New Missed Lines	%
src/github.lisp	1	0.0%
src/glossary.lisp	1	0.0%
src/locatives/glossary.lisp	1	0.0%
src/locatives/variable.lisp	1	41.51%
src/reference-api.lisp	1	19.23%
src/restart.lisp	1	0.0%
src/source-api.lisp	1	0.0%
src/swank.lisp	1	28.3%
src/full.lisp	2	0.0%
src/locatives/definers.lisp	2	0.0%
<!--	Total:	460		-->

Totals
Change from base Build 935441091:	2.2%
Covered Lines:	2813
Relevant Lines:	6599

---

💛 - Coveralls