Download blogger posts from blogger

[bryanbcook]

Expose a new method Get-BloggerPost with parameters:

• BlogId. Optional. If not provided the value is obtained from the user preferences
• PostId. Required.

Ideally, this could be combined with another function to persist to disk, or could be combined with other parameters:

• WorkingDirectory: Optional. path to a folder on disk
• FileNameFormat: Optional. Defaults to "{{Title}}", but could be expressed as "{{Date:YYYY}}{{Date:YYYY-MM-dd}}{{Title}}"
• Format:: Optional. Either HTML or Markdown