add how to import iiif impage into arkindex using cli

Write a section in the doc to explain how to import the images form storage.teklia.com on a arkindex instance

Test this procedure with MciT images

• add a link to https://pypi.org/project/arkindex-cli/
• add an example on a real dataset on iiif-europe.teklia.com server
• add the script to create the iiif urls from a liste of path

from urllib.parse import quote_plus
import sys
IIIF_SERVER = 'https://iiif-europe.teklia.com/iiif/2/'
for iiif_path in sys.stdin.readlines():
    iiif_url = IIIF_SERVER + quote_plus(iiif_path.strip())
    print (iiif_url)

cat file_list.txt | python generate_iiif_url.py > iiif_list.txt

• doc to install the needed python lib

arkindex upload iiif-images <iiif_url_list> <corpus_id> --import-folder-name <folder_name>