emails/templates: Use .txt.j2 file extension

This enables editors to realize that this is a template file.

Author: Turbo87

src/email.rs

@@ -32,19 +32,19 @@ static EMAIL_ENV: LazyLock<Environment<'static>> = LazyLock::new(|| {
         let email_name = dir_name.to_str();
         let email_name = email_name.expect("Invalid UTF-8 in email template directory name");
 
-        // Load subject.txt file
-        let subject_path = entry.path().join("subject.txt");
+        // Load subject.txt.j2 file
+        let subject_path = entry.path().join("subject.txt.j2");
         let subject_contents = std::fs::read_to_string(&subject_path)
             .expect(&format!("Failed to read subject template for {email_name}"));
-        let filename = format!("{}/subject.txt", email_name);
+        let filename = format!("{}/subject.txt.j2", email_name);
         env.add_template_owned(filename, subject_contents)
             .expect("Failed to add subject template");
 
-        // Load body.txt file
-        let body_path = entry.path().join("body.txt");
+        // Load body.txt.j2 file
+        let body_path = entry.path().join("body.txt.j2");
         let body_contents = std::fs::read_to_string(&body_path)
             .expect(&format!("Failed to read body template for {email_name}"));
-        let filename = format!("{}/body.txt", email_name);
+        let filename = format!("{}/body.txt.j2", email_name);
         env.add_template_owned(filename, body_contents)
             .expect("Failed to add body template");
     }
@@ -70,8 +70,8 @@ impl EmailMessage {
         template_name: &str,
         context: impl Serialize,
     ) -> Result<Self, minijinja::Error> {
-        let subject = render_template(&format!("{}/subject.txt", template_name), &context)?;
-        let body_text = render_template(&format!("{}/body.txt", template_name), context)?;
+        let subject = render_template(&format!("{}/subject.txt.j2", template_name), &context)?;
+        let body_text = render_template(&format!("{}/body.txt.j2", template_name), context)?;
 
         Ok(EmailMessage { subject, body_text })
     }