docs: add Voice & Style guide and rewrite docs pages to match

Add a Voice & Style section to the docs authoring guide, then bring every
docs page in line with it: lead with the task, add success signals to
procedures, explain jargon on first use, keep bullet casing consistent,
and link out to Troubleshooting where steps can fail.

Applied across English source and all localized versions (uk, zh-cn, es,
pt-br, ko, pl).

packages/docs/content/docs/troubleshooting.mdx

@@ -5,6 +5,8 @@ description: Common setup and runtime issues with quick fixes.
 
 # Troubleshooting
 
+Hit a snag? Find the symptom below and try the fix.
+
 ## OpenChamber command exits or fails to start
 
 - confirm Node.js `>=20`
@@ -23,8 +25,16 @@ description: Common setup and runtime issues with quick fixes.
 - restart tunnel from the same instance/port
 - regenerate connect link if previous token was already used
 
+See [Tunnels](/tunnels/) for the full setup, and [Reverse Proxy](/reverse-proxy/) if you run one.
+
 ## VS Code extension does not connect
 
 - confirm OpenChamber server is running
 - verify extension is updated
 - reload VS Code window and retry connection
+
+## Related
+
+- [Quickstart](/quickstart/)
+- [Tunnels](/tunnels/)
+- [Reverse Proxy](/reverse-proxy/)