Added documentation to start

project/src/backend.rs

@@ -54,6 +54,23 @@ impl Backend {
     pub fn get_memberships(&self) -> Vec<String> {
         self.memberships.clone()
     }
+    /// Calculates the Prorate with the given parameters
+    ///
+    /// Memberships need to be in the format of: _"MEMBERSHIPNAME ($PRI.CE)"_
+    ///
+    /// # Arguments
+    /// * `current_membership` - The text content of what current membership you have
+    /// * `new_membership` - The text content of what new membership you're getting
+    /// * `last_billing` - The date of the last time the customer got billed _(mm/dd/yyyy)_
+    ///
+    /// # Examples
+    /// ```rs
+    /// let result = calculator.start(
+    ///     "Super ($41.99)".to_string(),
+    ///     "Deluxe ($36.99)".to_string(),
+    ///     "7/16/2025".to_string()
+    /// )?;
+    /// ```
     pub fn calculator_start(
         &self,
         current_membership: String,

project/src/backend/calculator.rs

@@ -66,9 +66,21 @@ impl Calculator {
     // Functions
     /// Calculates the Prorate with the given parameters
     ///
+    /// Memberships need to be in the format of: _"MEMBERSHIPNAME ($PRI.CE)"_
+    ///
     /// # Arguments
+    /// * `current_membership` - The text content of what current membership you have
+    /// * `new_membership` - The text content of what new membership you're getting
+    /// * `last_billing` - The date of the last time the customer got billed _(mm/dd/yyyy)_
     ///
     /// # Examples
+    /// ```rs
+    /// let result = calculator.start(
+    ///     "Super ($41.99)".to_string(),
+    ///     "Deluxe ($36.99)".to_string(),
+    ///     "7/16/2025".to_string()
+    /// )?;
+    /// ```
     pub fn start(
         &self,
         current_membership: String,