George Kalpakas a086976d68 fix(docs-infra): improve heading styles (#40427)
This commit includes some general improvements to heading styles
(font-weight, margin/padding). It also adds a horizontal separator above
`<h2>` headings to segment important sections more easily.
(As a consequence, we can remove several `<hr />` elements right before
`<h2>` headings.)

Co-authored-by: Stefanie Fluin <sjtrimble@gmail.com>

PR Close #40427
2021-02-02 12:04:55 -08:00
..