Remove Glob from JSON example

[SJaffa]

programming_with_python/_episodes/02-dictionaries.md

Line 348 in 19edfb7

import glob

If glob hasn't been already introduced this is unneccesary cognitive load, would be best to just show reading in a single JSON file.

[SJaffa]

This was completed in e95b85088c5966ad44f9ba8deab5a6da5b7960a2