Update help text to cover input file format handling.

src/Resources/Resources/help/New-AzPolicyDefinition.md

@@ -56,7 +56,12 @@ The **New-AzPolicyDefinition** cmdlet creates a policy definition that includes
 PS C:\> New-AzPolicyDefinition -Name 'LocationDefinition' -Policy C:\LocationPolicy.json
 ```
 
-This command creates a policy definition named LocationDefinition that contains the policy rule specified in C:\LocationPolicy.json. Example content for the LocationPolicy.json file is provided above.
+This command creates a policy definition named LocationDefinition that contains the policy rule specified in C:\LocationPolicy.json. Example content for the LocationPolicy.json file is provided above. Three file content formats are supported:
+1. Policy rule only (example above).
+2. Policy properties object. This format is displayed in the portal when editing a policy definition and may include parameters.
+3. Full policy object. This format is generated by the Azure Policy export function and may include parameters.
+
+Note: Values provided on the command line (e.g. parameters, metadata) override corresponding values present in the file.
 
 ### Example 2: Create a parameterized policy definition using inline parameters
 ```