* Added draft release notes for 0.8
* Moved some content to 'advanced' section.
* Added conceptual documentation for actions, caching and logging.
* Updated site footer.
Repository.Token() generates a base64-encoded token that can
be stored in password manager that fully describes repository connection
information (blob.ConnectionInfo) and optionally a password.
Use `kopia repo status -t` to print the token.
Use `kopia repo status -t -s` to print the token that also includes
repository password.
Use `kopia repo connect from-config --token T` to reconnect using the
token.
