dotcom: desc tweak (#3885)

super minor tweak

### Change Type

<!-- ❗ Please select a 'Scope' label ❗️ -->

- [ ] `sdk` — Changes the tldraw SDK
- [x] `dotcom` — Changes the tldraw.com web app
- [ ] `docs` — Changes to the documentation, examples, or templates.
- [ ] `vs code` — Changes to the vscode plugin
- [ ] `internal` — Does not affect user-facing stuff

<!-- ❗ Please select a 'Type' label ❗️ -->

- [ ] `bugfix` — Bug fix
- [ ] `feature` — New feature
- [x] `improvement` — Improving existing features
- [ ] `chore` — Updating dependencies, other boring stuff
- [ ] `galaxy brain` — Architectural changes
- [ ] `tests` — Changes to any test code
- [ ] `tools` — Changes to infrastructure, CI, internal scripts,
debugging tools, etc.
- [ ] `dunno` — I don't know

apps/dotcom/index.html

@@ -15,7 +15,7 @@
 		<meta name="apple-mobile-web-app-title" content="tldraw" />
 		<link rel="mask-icon" href="/safari-pinned-tab.svg" color="#FFFFFF" />
 
-		<meta name="description" content="A free and instant collaborative diagramming tool." />
+		<meta name="description" content="A free and instant collaborative whiteboarding tool." />
 		<meta name="format-detection" content="telephone=no" />
 		<meta name="mobile-web-app-capable" content="yes" />
 		<meta name="msapplication-config" content="browserconfig.xml" />
@@ -30,12 +30,18 @@
 		<meta name="twitter:card" content="summary" />
 		<meta name="twitter:url" content="https://www.tldraw.com/" />
 		<meta name="twitter:title" content="tldraw" />
-		<meta name="twitter:description" content="A free and instant collaborative diagramming tool." />
+		<meta
+			name="twitter:description"
+			content="A free and instant collaborative whiteboarding tool."
+		/>
 		<meta name="twitter:image" content="https://www.tldraw.com/social-twitter.png" />
 		<meta name="twitter:creator" content="@tldraw" />
 		<meta property="og:type" content="website" />
 		<meta property="og:title" content="tldraw" />
-		<meta property="og:description" content="A free and instant collaborative diagramming tool." />
+		<meta
+			property="og:description"
+			content="A free and instant collaborative whiteboarding tool."
+		/>
 		<meta property="og:site_name" content="tldraw" />
 		<meta property="og:url" content="https://www.tldraw.com/" />
 		<meta property="og:image" content="https://www.tldraw.com/social-og.png" />