<name> is the bundle, with or without its .monsecrets suffix; a path works
too. The bundle is deleted only once every secret is stored and the file is
written, since by then it has done its job and a copy left behind is one more
thing to lose. --keep leaves it where it was, for a bundle you are handing
on to someone else.
The file goes at the root of the git checkout, the way .gitignore sits at
the root, so monkeys run works from any directory in it. Outside a checkout
it goes in the current directory, and a second argument names the directory
outright. When a .monkeys file is already there, unpack adds a block at
the end for the keys the file does not yet list, grouped the way the bundle
groups them, and leaves the rest of the file alone. A file that names another
project on its + line refuses the bundle, and the bundle stays.
The passphrase is read from standard input when it is not a terminal.