feat: Add current semester to semesters if not specified

Fixes: #1

src/courses.rs

@@ -66,6 +66,11 @@ impl Course {
         &self.semesters
     }
 
+    /// Get a reference to the course's semesters.
+    pub fn semesters_mut(&mut self) -> &mut Vec<String> {
+        &mut self.semesters
+    }
+
     /// Check if course is part of current semester
     pub fn is_current(&self) -> bool {
         self.semesters()

src/main.rs

@@ -66,7 +66,10 @@ fn main() -> Result<()> {
     Ok(())
 }
 
-fn add(course: Course, debug: bool) -> Result<()> {
+fn add(mut course: Course, debug: bool) -> Result<()> {
+    if course.semesters().is_empty() {
+        course.semesters_mut().push(util::get_current_semester())
+    }
     let toml = toml::to_string(&course)?;
     println!("{}", toml);
     let target_dir = [