Add a verbose/quiet pair of flags

src/args.rs

@@ -1,6 +1,7 @@
 use std::path::PathBuf;
 
 use clap::{command, Parser, Subcommand};
+use clap_verbosity_flag::{InfoLevel, Verbosity};
 use serde::Serialize;
 
 #[derive(Parser, Serialize)]
@@ -27,6 +28,10 @@ pub(crate) struct Opts {
     #[command(subcommand)]
     #[serde(flatten)]
     pub command: Commands,
+
+    #[command(flatten)]
+    #[serde(skip)]
+    pub verbose: Verbosity<InfoLevel>,
 }
 
 #[derive(Serialize, Subcommand)]
@@ -78,7 +83,7 @@ pub(crate) enum PeopleCommands {
     /// Synchronises date of births from a vcard file
     #[serde(rename = "sync_date_of_births")]
     SyncDateOfBirths {
-        #[arg(short, long)]
+        #[arg(long)]
         #[serde(skip_serializing_if = "::std::option::Option::is_none")]
         vcard: Option<PathBuf>,
     },