[docs] design shuffle (#2951)

This PR incorporates design tweaks from #2922 without the home page or
content changes.

These are:
- Replacing all `hello@tldraw.com` with `sales@tldraw.com`
- Fix mailto links.
- Showing the first item in a section on direct routes to the section
- Splitting the article page for human-written content from article page
for generated content
- Splitting the layout for the landing page from the rest of the site
(temporarily identical to the regular content)
- Removing headings from left sidebar
- Restoring headings in right sidebar for human-written pages with > 1
heading link
- Styling block quote
- Adjusting section link appearance / layout in header / menu
- Changing the order of search results to preference docs over examples
- Updating copy on events
- Removing copy on user interface menus
- Adding hero as prop to all articles
- Updated icon
- Fixing a few broken links
- Replaces the sandpack code blocks with hljs code blocks, except in
examples.

### Change Type

- [x] `documentation` — Changes to the documentation only[^2]

apps/docs/scripts/functions/getApiMarkdown.ts

@@ -217,7 +217,7 @@ async function addDocComment(result: Result, member: ApiItem) {
 
 		if (exampleBlocks.length) {
 			result.markdown += `\n\n`
-			result.markdown += `##### Example\n\n`
+			result.markdown += `<ApiHeading>Example</ApiHeading>\n\n`
 			for (const example of exampleBlocks) {
 				result.markdown += await MarkdownWriter.docNodeToMarkdown(member, example.content)
 			}
@@ -393,7 +393,7 @@ function addTags(result: Result, member: ApiItem) {
 		tags.push('readonly')
 	}
 	tags.push(member.kind.toLowerCase())
-	result.markdown += `<Small>${tags.join(' ')}</Small>\n\n`
+	result.markdown += `<Small>${tags.filter((t) => t.toLowerCase() !== 'none').join(' ')}</Small>\n\n`
 }
 
 function addReferences(result: Result, member: ApiItem) {