Update AWS SSM Parameter Store secret store docs

[ostreek]

What content needs to be created or modified?
The documentation for the AWS SSM Parameter Store secret store needs to be updated for dapr/components-contrib#2001. I also noticed there's functionality to retrieve a specific version of a parameter, but this isn't documented.

Describe the solution you'd like
The prefix option needs to be documented. Ideally the parameter store docs would have an example section like Azure Key Vault has.

Where should the new material be placed?
In the AWS SSM Parameter Store component spec.
The option to retrieve a specific version of a parameter should also be mentioned in the API reference.