message: style(page): increase default page width -> 720px
diff: docs-page {
  display: grid;
  font-size: 15px;
  - grid-template-columns: minmax(0, var(--page-width, 680px)) 1fr;
  + grid-template-columns: minmax(0, var(--page-width, 720px)) 1fr;
  line-height: 2;
  margin-left: var(--page-margin-left, var(--menu-width));
  margin-top: var(--header-height);
  