Clarify how "alias.foo = : git cmd ; aliased-command-string" should
be spelled with necessary whitespaces around punctuation marks to
work.
* pb/completion-aliases-doc:
completion: improve doc for complex aliases
# completion style. For example '!f() { : git commit ; ... }; f' will
# tell the completion to use commit completion. This also works with aliases
# of form "!sh -c '...'". For example, "!sh -c ': git commit ; ... '".
+# Be sure to add a space between the command name and the ';'.
#
# If you have a command that is not part of git, but you would still
# like completion, you can use __git_complete: