Add hint panels

[HEdingfield]

• Most likely use a TextFlow element per this example

• Hint panel may need to be created programmatically so it can make space for tables (since, if you just toggle visibility, it doesn't move any other elements around on the page)

  • Alternatively, using an accordion element might work well enough

• The mock-up has tooltips for every single element, but @chughes297 said:

  On the tooltips vs hint box question. I think if we can have the hint box recallable by a user after it disappears, we don't also need tooltips.

• Instead of making the output directory a required field (per the mock-up), add a hint saying blank will write it to the same location as the config file (verify this is what it does)

[HEdingfield]

Good stopgap idea: use the side panel (would actually need to move it into each individual tab) and put the hints in there, sorting them in separate .txt files.

[HEdingfield]

For future reference, there are some options to render Markdown in JavaFX using third-party libraries like those mentioned here.

[HEdingfield]

#511 implemented stopgap solution mentioned above. Opened #513 for future enhancements.