say which churches are missing, and why, instead of guessing them

Ten of the fourteen Byzantine-rite Eastern Catholic churches are absent. The
honest reason is that their calendars could not be verified: general
references do not record whether the Slovak, Hungarian, Krizevci,
Italo-Albanian, Greek, Bulgarian, Macedonian, Belarusian, Russian or Albanian
churches keep Pascha with Rome or with the local Orthodox, and the churches'
own sites render their liturgical calendars in JavaScript. Inferring it from
geography would put an unsourced claim in the one place this program exists to
be right about.

Nobody needs an entry to get a correct calendar, though, and both --list and
the README now say so: one question to a parish picks one of the three
reckonings, which between them cover every combination there is.

src/main.rs

@@ -149,6 +149,17 @@ fn list_jurisdictions() {
         }
         println!();
     }
+    println!("  Not listed? There are fourteen Byzantine-rite Eastern Catholic");
+    println!("  churches and ten of them are not here, because their calendars");
+    println!("  could not be verified against anything published. Ask your parish");
+    println!("  one question: is Pascha kept with Rome or with the local");
+    println!("  Orthodox? The answer picks a reckoning above:\n");
+    println!("    with Rome, fixed feasts on the civil calendar   --calendar western");
+    println!("    with the Orthodox, fixed feasts on the civil     --calendar new");
+    println!("    with the Orthodox, fixed feasts thirteen days    --calendar old");
+    println!("                                                     behind\n");
+    println!("  A patch adding your church, with a source for its calendar, is");
+    println!("  welcome.\n");
 }
 
 fn elide(text: &str, width: usize) -> String {