Upgrades for feedback file

[CatalinaMedina]

• Add capability for user to specify an existing feedback file that we will just append the text to
• Add option to print grade decomposition to feedback file

[federicazoe]

#18 mentions this

[mdogucu]

Is there a specific reason why .qmd cannot be used for the feedback file? I got this error:

Error in core_assist_grading(rubric_path = rubric_path, roster_path = roster_path, :
The extension of the example_feedback_path must be one of the following: '.Rmd', '.docx', '.html', '.pdf'.

[mdogucu]

Just noticed #8