TBH I usually just search my shell history for the last time I added a remote and edit it.
It's also not particularly hard to write a shell function to avoid needing to care about the syntax, e.g.:
add_github_remote() { git remote add $1 [email protected]:$2/$3.git }
It's also not particularly hard to write a shell function to avoid needing to care about the syntax, e.g.: