Add Implementation part headers by default for main component in SSP Markdown

[jpower432]

Issue description / feature objectives

Implementation part headers (e.g ### Implementation part a.) appear in the SSP Markdown for components when rules are attached. There may be use cases when a high level response is needed at the statement level for the overall system with no rules attached. The main component This System is an example of this.

Caveats / Assumptions

• Assumption - This System would be used to provide overall system responses and context so the user would need to be able to provide that at the statement level.
• Assumption - This System would not have rules attached

Completion Criteria

• The ### Implementation part <statement label> would appear by default for the This System component when generating SSP Markdown.