doc: Clarify import keys operation further.
doc: Clarify import keys operation further.

* doc/gpgme.texi (gpgme_op_import_keys): Further clarifications.

Signed-off-by: Marcus Brinkmann <77666125932addc6fc525b281b518fd8fd2203d8@g10code.com>
GnuPG-bug-id: 3215

gpg/gpgme,gpg/gpgme,gpg/gpgme,gpg/gpgme,gpg/gpgme,gpg/gpgme,gpg/gpgme