feat(pcli) default to phase 2 for ceremony

As plan to transition to phase 2 of the summoning ceremony along with
the release of Testnet 65. Here we update the default value for
`pcli ceremony contribute --phase` to be `2`, rather than a required
arg. The summoning website already displays an explicit example command,
and the value for "phase" is determined by the phase of the coordinator
server, so no changes needed there.

crates/bin/pcli/src/command/ceremony.rs

@@ -80,12 +80,21 @@ async fn handle_bid(app: &mut App, to: Address, from: AddressIndex, bid: &str) -
 pub enum CeremonyCmd {
     /// Contribute to the ceremony
     Contribute {
-        #[clap(long)]
+        /// The phase of the summoning ceremony that's currently active. Must match that of the remote
+        /// coordinator.
+        #[clap(long, default_value = "2")]
         phase: u8,
+        /// The URL for the public coordination server.
         #[clap(long, default_value = "https://summoning.penumbra.zone")]
         coordinator_url: Url,
+        /// The Penumbra wallet address of the coordination server. Bids will be sent to this
+        /// address, so the coordinator can compute the contributor's place in the queue.
         #[clap(long)]
         coordinator_address: Address,
+        /// Amount to spend during bid. Must be specified typed values, e.g. '50penumbra'.
+        /// Only the 'penumbra' token is accepted for contributions. Bids are additive,
+        /// so if you're disconnected, you can bid '0penumbra' and your previous bids
+        /// will be still be counted when computing your place in the queue.
         #[clap(long)]
         bid: String,
     },