Add documentation for GÉANT IP service related code

...source/module/workflows/edge_port/terminate_edge_port.rst

docs/vale/.vale.ini

docs/vale/styles/config/vocabularies/geant-jargon/accept.txt

docs/vale/styles/custom/Contractions.yml

gso/products/product_blocks/edge_port.py

gso/products/product_blocks/geant_ip.py

gso/products/product_blocks/opengear.py

gso/services/kentik_client.py

gso/services/netbox_client.py

gso/translations/en-GB.json

gso/utils/helpers.py

gso/workflows/edge_port/create_edge_port.py

gso/workflows/edge_port/terminate_edge_port.py

gso/workflows/geant_ip/create_geant_ip.py

gso/workflows/iptrunk/create_iptrunk.py

gso/workflows/iptrunk/migrate_iptrunk.py

gso/workflows/iptrunk/modify_trunk_interface.py

gso/workflows/iptrunk/validate_iptrunk.py

gso/workflows/router/create_router.py

gso/workflows/router/modify_connection_strategy.py