Add paragraph spacing options

[munichPMN]

What problem does this feature solve?

The existing program solely permits adjustments to line spacing. By incorporating paragraph spacing options, users gain enhanced document formatting capabilities, leading to heightened readability and improved presentation.

Additionally, it would be beneficial to have the flexibility to change units within the program. While the default unit appears to be pixels (px), offering the option to switch to points (pt) or other units would greatly enhance user convenience and adaptability to diverse formatting preferences.

What does the proposed API look like?

The proposed API would add two new properties to the Paragraph class: BeforeSpacing AfterSpacing
These properties would allow users to specify the amount of space before and after each paragraph.