Update project description for HTML5 CSS (pypi#12080)

* feat: render inline literals as code

Docutils HTML5 writer has decided that the emitted style for inline
literals will no longer inherit the (deprecated) `tt` style, rather
place the onus on the author to declare what kind of style to apply to a
literal.

Refs: https://sourceforge.net/p/docutils/bugs/393/

Signed-off-by: Mike Fiedler <miketheman@gmail.com>

* fix: reduce margins included in table cells

docutils HTML5 writer adds `<p>` tags to cells in tables, adding
margins, and bloating the overall size.

Docutils has an inline TODO, contemplating removing this behavior:
https://sourceforge.net/p/docutils/code/HEAD/tree/tags/docutils-0.19/docutils/writers/_html_base.py#l1381

Until such time, inherit the same margins for the `th/td` attributes.

Signed-off-by: Mike Fiedler <miketheman@gmail.com>

* feat: render description lists as grid items

Docutils HTML5 changes the output for lists like `docinfo` and
`field-list` to no longer have `table` semantics, preferring to lean on
CSS to place and style them.

This isn't 100% the same as before, but it's close enough for a
reasonable display.

Signed-off-by: Mike Fiedler <miketheman@gmail.com>

Signed-off-by: Mike Fiedler <miketheman@gmail.com>
Co-authored-by: Dustin Ingram <di@users.noreply.github.com>

warehouse/static/sass/base/_typography.scss

@@ -40,7 +40,8 @@ code,
 kbd,
 pre,
 samp,
-tt {
+tt,
+.docutils.literal {
   font-family: $code-font;
   background-color: lighten($base-grey, 5);
   border: 1px solid $border-color;

warehouse/static/sass/blocks/_project-description.scss

@@ -149,6 +149,24 @@
   dl {
     margin: ($spacing-unit / 2) 0 0 0;
 
+    &.docinfo,
+    &.field-list {
+      display: grid;
+      grid-template-columns: max-content auto;
+
+      dt {
+        grid-column-start: 1;
+
+        &:first-of-type {
+          margin-top: ($spacing-unit / 2); // override inherited _lists.scss
+        }
+      }
+
+      dd {
+        grid-column-start: 2;
+      }
+    }
+
     dt {
       font-weight: $bold-font-weight;
     }
@@ -177,6 +195,10 @@
       border: 0;
       padding: 10px 7px;
       border-right: 1px solid $border-color;
+
+      p {
+        margin: inherit;
+      }
     }
 
     thead tr {