Rename generate-lockfiles to lock

[Eric-Arellano]

We should have named it this before. It's much shorter and several users have expressed they'd prefer this.

Even though we want it so you don't have to run the goal explicitly much via #12014, it is still useful to do this.

[da-tubi]

lock is a better name!

[da-tubi]

Accessibility is very important!

Assuming I'm a Chinese programmer who are not good at English, I will have trouble spelling the word generate.

And why I need to remember if I should use generate-lockfiles or generate-lockfile?