Improve how Input and Output markdown headers handles array types.

[powercode]

PR Summary

Improve how Input and Output headers array types are handled when reading markdown.

PR Context

Input/Output type should read tokens of the inputOutputHeader.
For example:
System.String[] is currently parsed as the first token, System.String, skipping the second and third ([, ]).

With this change, the array types are parsed correctly.

Sample markdown:

## INPUTS

### System.String[]

You can pipe strings or string arrays to the cmdlet.