doc.css: uniformize list item margins

This patch makes the margins of definition, unordered, and ordered list
items uniform.

The visual rules are:

* No margin between a definition term (`<dt>`) and its definition
  (`<dd>`):

      Shock:
        Culpa cupidatat irure.

      Idea:
        Guide:
          Lorem ipsum in sit cupidatat.

          Sint nisi laboris.

        Quarter:
          In sunt.

      Memory:
        * Stop

        * Wall

* No margin between adjacent definition terms (`<dt>`):

      Shock:
        Culpa cupidatat irure.

      Idea:
      Desk:
      Judicial:
        Lorem ipsum in sit cupidatat.

      Design:
        Est occaecat labore.

* A margin between unordered/ordered list items (`<li>`):

      * Foundation

      * Recycle

        - Slide

        - Crown

      * Operation

  Although this can look unnatural for lists with simple items, it
  becomes natural when a list item contains more contents:

      * Foundation

      * Mollit ut eu dolore.

        Nostrud pariatur in in sit voluptate minim ut amet commodo elit
        laboris id do adipisicing do qui ex in esse ut voluptate fugiat
        adipisicing elit in enim aute fugiat dolore proident sint
        proident dolor:

        - Aute in mollit dolore duis laboris irure in magna ea anim nisi
          pariatur sed amet qui fugiat dolor culpa excepteur cillum id
          laboris eiusmod velit in.

          Permanent:
            Lorem ipsum veniam sed do dolore nostrud voluptate in do
            dolore in quis.

          Jacket:
          Waterfall:
            Ea voluptate officia nostrud.

            Reprehenderit aliqua sed laborum minim est voluptate ullamco
            fugiat quis nisi cupidatat ex eu ad sint enim.

        - Lorem ipsum amet dolor laboris.

      * Aliqua sunt duis irure veniam sit amet fugiat excepteur et
        dolore ut exercitation in in sunt est do excepteur consectetur
        irure exercitation ut cupidatat veniam ut ullamco eu dolor quis
        laboris est.

        Lorem ipsum sit cupidatat mollit occaecat.

        Aliqua veniam.

  Now all those paragraphs have natural margins even if their structures
  are lists.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
3 jobs for fix-list-margins in 4 minutes and 7 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Setup
passed #737323750
install

00:01:26

 
  Verify
passed #737323751
lint

00:01:18

 
  Deploy
passed #737323752
bundle-dev

00:01:22