about-key-servers.page: Mark for review

Reworded bits and pieces, marked for review.
about-subkeys.page: Remove comma.
about-keyring.page: Removed bits.

Default UI has changed.
(Refer commit	c375a820447a792539fad4cecdb7e21e86c62fc2)
Reword passwords-keyring-create.page
passwords-keyring-create.page: Add link

Link to about-keyring.page