Updated README to accurately reflect directory contents

Doc/DevelopmentPlan/README.md

 # Development Plan
 
 The folders and files for this folder are as follows:
-
-Describe ...
+<p><br></br></p>
+| File | Description |
+| -------- | ------- |
+| **DevelopmentPlan.pdf** | Official development plan document |
+| ProblemStatement.tex | TeX file which generates the development plan PDF |
+| DevPlanMarkingScheme.pdf | Marking scheme reference |
+| Gantt Ideas.txt | Rough deadline estimates |
+| ProposedUTFrameworks.txt | List of unit test frameworks under consideration |
+| WorkDist.txt | Distribution of work for the development plan |