Update windows installer script to be multi-realm aware [skip-ci]
@@ -27,7 +27,7 @@ to install the agent. The agent will be installed as a Windows service and will
log to the Windows Event Log.
```sh
-& {Set-ExecutionPolicy Bypass -Scope Process -Force; $script = ((New-Object System.Net.WebClient).DownloadString('https://dl.signalfx.com/signalfx-agent.ps1')); $params = @{access_token = "YOUR_SIGNALFX_API_TOKEN"}; Invoke-Command -ScriptBlock ([scriptblock]::Create(". {$script} $(&{$args} @params)"))}
+& {Set-ExecutionPolicy Bypass -Scope Process -Force; $script = ((New-Object System.Net.WebClient).DownloadString('https://dl.signalfx.com/signalfx-agent.ps1')); $params = @{access_token = "YOUR_SIGNALFX_API_TOKEN"; ingest_url = "https://ingest.YOUR_SIGNALFX_REALM.signalfx.com"; api_url = "https://api.YOUR_SIGNALFX_REALM.signalfx.com"}; Invoke-Command -ScriptBlock ([scriptblock]::Create(". {$script} $(&{$args} @params)"))}
```
Your SignalFx API Token can be obtained from the Organization->Access Token tab in [SignalFx](https://app.signalfx.com).
