Additional metadata snippets support

[vicperdana]

PSDocs supports the following metadata - these should be added to the snippet examples.

Field	Scope	Type	Description
name	Template	string	Used for markdown page title.
summary	Template	string	Used as a short description for the markdown page.
description	Template	string	Used as a detailed description for the markdown page.
description	Parameter	string	Used as the description for the parameter.
example	Parameter	string, boolean, object, or array	An example use of the parameter. The example is included in the JSON snippet. If an example is not included the default value is used instead.
ignore	Parameter	boolean	When true the parameter is not included in the JSON snippet.
description	Output	string	Used as the description for the output.