fix(actions): warn on unknown injects

Resolves #20

src/actions/actions.rs

@@ -197,11 +197,20 @@ impl Echo {
     let mut message = message.unindent();
 
     if let Some(injects) = &self.injects {
+      let mut should_print_nl = false;
+
       for inject in injects {
         if let Some(value) = state.get(inject) {
           message = message.replace(&format!("{{{inject}}}"), value.to_string().as_str());
+        } else {
+          println!("{}", format!("? Unknown injection: {inject}").yellow());
+          should_print_nl = true;
         }
       }
+
+      if should_print_nl {
+        println!();
+      }
     }
 
     Ok(println!("{message}"))
@@ -217,11 +226,20 @@ impl Run {
     let spinner = Spinner::new();
 
     if let Some(injects) = &self.injects {
+      let mut should_print_nl = false;
+
       for inject in injects {
         if let Some(value) = state.get(inject) {
           command = command.replace(&format!("{{{inject}}}"), value.to_string().as_str());
+        } else {
+          println!("{}", format!("? Unknown injection: {inject}").yellow());
+          should_print_nl = true;
         }
       }
+
+      if should_print_nl {
+        println!();
+      }
     }
 
     let name = self