Documentation: be consistent about "git-" versus "git "

Documentation: be consistent about "git-" versus "git "

Since the git-* commands are not installed in $(bindir), using
"git-command <parameters>" in examples in the documentation is
not a good idea. On the other hand, it is nice to be able to
refer to each command using one hyphenated word. (There is no
escaping it, anyway: man page names cannot have spaces in them.)

This patch retains the dash in naming an operation, command,
program, process, or action. Complete command lines that can
be entered at a shell (i.e., without options omitted) are
made to use the dashless form.

The changes consist only of replacing some spaces with hyphens
and vice versa. After a "s/ /-/g", the unpatched and patched
versions are identical.

Signed-off-by: Jonathan Nieder <redacted>
Signed-off-by: Junio C Hamano <redacted>