Fixed main.py: Correct file reading and JSON formatting

[217785-collab]

Error 1: Fixed path_to_file_list (lines 4–7)

1. Changed open(path, 'w') → open(path, 'r') because 'w' wipes the file and prevents reading.
2. Fixed return lines → proper list comprehension.

Error 2: Fixed JSON generation in train_file_list_to_json

1. Removed incorrect conditions like if '/' or '"' in file: which always evaluate to true.
2. Replaced broken template-based JSON with json.dumps.
3. Corrected incorrect variable overwrite: english_file = process_file(german_file).

Error 3: Fixed write_file_list (lines 27–31)

1. Changed open(path, 'r') → open(path, 'w') because writing was impossible.
2. Added actual writing of the content (f.write(line + "\n")).

Error 4: Fixed the main function logic

1. Original code passed wrong arguments to functions and used wrong return values.
2. Replaced with correct calls: