Display Build Size Difference

Created by: elijahmanor

This PR closes #326 (closed)

Test Plan

1. Run npm run build without a build folder
   • Should not show any difference
2. Run npm run build with a build folder with no changes
   • Should show a green positive difference of zero
   • example: (+0 B)
3. Run npm run build with a build folder after adding new code
   • Should show a red positive difference of some number
   • example: (+3 B)
4. Run npm run build with a build folder after removing old code.
   • Should show green negative difference of some number
   • example: (-3 B)