Examples:
# Opens the interactive interface to add a new dynamic variable completion
intelli-shell completion new -i
# Adds a dynamic completion for any variable called {{branch}} on 'git' commands
intelli-shell completion new --command git branch "git branch --format='%(refname:short)'"
# Open the interactive interface, using ai to suggest a provider for {{container}} variable globally
intelli-shell completion new -i --ai container