Fix capitalization of boolean type in parameter definition

Corrected capitalization of 'Boolean' to 'boolean' in parameter type description.

Author: rmcmurray

articles/governance/policy/concepts/definition-structure-parameters.md

@@ -20,7 +20,7 @@ Parameters can't be removed from a policy definition because there might be an a
 A parameter uses the following properties in a policy definition:
 
 - `name`: The name of your parameter. Used by the `parameters` deployment function within the policy rule. For more information, see [using a parameter value](#using-a-parameter-value).
-- `type`: Determines if the parameter is a `string`, `array`, `object`, `Boolean`, `integer`, `float`, or `dateTime`. (`dateTime` parameters should be in ISO 8601 `yyyy-MM-ddTHH:mm:ss.fffffffZ` format.)
+- `type`: Determines if the parameter is a `string`, `array`, `object`, `boolean`, `integer`, `float`, or `dateTime`. (Where `dateTime` parameters should be in ISO 8601 `yyyy-MM-ddTHH:mm:ss.fffffffZ` format.)
 
 - `metadata`: Defines subproperties primarily used by the Azure portal to display user-friendly information:
   - `description`: The explanation of what the parameter is used for. Can be used to provide examples of acceptable values.