* networking/stubby.nix: implementing systemd service module for stubby
This change implements stubby, the DNS-over-TLS stub resolver daemon.
The motivation for this change was the desire to use stubby's
DNS-over-TLS funcitonality in tandem with unbound, which requires
passing certain configuration parameters. This module implements those
config parameters by exposing them for use in configuration.nix.
* networking/stubby.nix: merging back module list
re-merging the module list to remove unecessary changes.
* networking/stubby.nix: removing unecessary capabilities flag
This change removes the unecessary flag for toggling the capabilities
which allows the daemon to bind to low ports.
* networking/stubby.nix: adding debug level logging bool
Adding the option to turn on debug logging.
* networking/stubby.nix: clarifying idleTimeout and adding systemd target
Improving docs to note that idleTimeout is expressed in ms. Adding the
nss-lookup `before' target to the systemd service definition.
* networking/stubby.nix: Restrict options with types.enum
This change restricts fallbackProtocol and authenticationMode to accept
only valid options instead of any list or str types (respectively). This
change also fixes typo in the CapabilityBoundingSet systemd setting.
* networking/stubby.nix: cleaning up documentation
Cleaning up docs, adding literal tags to settings, and removing
whitespace.
* networking/stubby.nix: fixing missing linebreak in comments
* networking/stubby.nix: cleaning errant comments
