docs: label tls troubleshooting examples by platform

Author: PatrickJS

rules/network-troubleshoot.mdc

@@ -78,11 +78,15 @@ curl -I https://<target-host>/<path>
 
 ### TLS
 
+Linux/macOS:
+
 ```bash
 openssl s_client -connect <target-host>:443 -showcerts </dev/null
 echo | openssl s_client -connect <target-host>:443 2>/dev/null | openssl x509 -noout -dates
 ```
 
+Windows PowerShell:
+
 ```powershell
 try {
   $req = [Net.HttpWebRequest]::Create("https://<target-host>")