fix: enable partial defaults in config

lib/main.rs

@@ -44,10 +44,21 @@ impl Default for TagState {
     }
 }
 
+fn default_true() -> bool {
+    true
+}
+
+fn default_3() -> u8 {
+    3
+}
+
 #[derive(Deserialize)]
 pub struct Config {
+    #[serde(default = "default_3")]
     pub prepopulate: u8,
+    #[serde(default = "default_true")]
     pub strict: bool,
+    #[serde(default = "default_true")]
     pub activation_on_fill: bool,
 }