[docs] Add information about trace verbosity (#18093)

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Author: anthony-c-martin

docs/troubleshooting.md

@@ -1,4 +1,6 @@
-## Tracing
+# Tracing
+
+## Enabling
 To collect troubleshooting information, it can be useful to enable detailed tracing. To do this, run one of the following commands in your console window before invoking Bicep:
 
 1. (Mac/Linux) Run the following:
@@ -9,3 +11,16 @@ To collect troubleshooting information, it can be useful to enable detailed trac
    ```powershell
    $env:BICEP_TRACING_ENABLED = $true
    ```
+
+## Controlling Verbosity
+
+The default verbosity for tracing is "basic". In addition to [enabling tracing](#enabling), you can also set the verbosity to "full" to capture all tracing details:
+
+1. (Mac/Linux) Run the following:
+   ```sh
+   export BICEP_TRACING_VERBOSITY=full
+   ```
+1. (Windows) Run the following in a PowerShell window:
+   ```powershell
+   $env:BICEP_TRACING_VERBOSITY = "full"
+   ```