[ENHANCEMENT] Add a method to list supported scripts for LookupData

[iwpnd]

There is currently now way to list the supported scripts that reside in /resources/script.json other than

from flashgeotext import settings

print(settings.SCRIPTS.keys())

>> dict_keys(['cyrillic', 'ascii', 'latin', 'syriac', 'ethiopic', 'arabic', 'bengali', 'balinese', 'bamum', 'devanagari', 'tai_viet', 'tibetan', 'bassah_vah', 'buginese', 'chakma', 'cherokee', 'canadian_aboriginal', 'thaana', 'greek', 'adlam', 'gujarati', 'hebrew', 'armenian', 'yi', 'javanese', 'georgian', 'new_tai_lue', 'thai_tham', 'khmer', 'kannada', 'lisu', 'lao', 'mandaic', 'malayalam', 'myanmar', 'n_ko', 'oriya', 'gurmukhi', 'tifinagh', 'sinhala', 'sundanese', 'tamil', 'tai_le', 'telugu', 'thai', 'vai'])

so add a method to show the user the supported scripts in a better way.