docs: add some specification

Endpoint/Controllers/V1/ScheduleController.cs

@@ -21,10 +21,18 @@ namespace Mirea.Api.Endpoint.Controllers.V1;
 [CacheMaxAge(true)]
 public class ScheduleController(IMediator mediator, IOptionsSnapshot<GeneralConfig> config) : BaseController
 {
+    /// <summary>
+    /// Retrieves the start term for the schedule.
+    /// </summary>
+    /// <returns>The start term as a <see cref="DateOnly"/> value.</returns>
     [CacheMaxAge(1, 0)]
     [HttpGet("StartTerm")]
     public ActionResult<DateOnly> GetStartTerm() => config.Value.ScheduleSettings!.StartTerm;
 
+    /// <summary>
+    /// Retrieves the pair periods.
+    /// </summary>
+    /// <returns>A dictionary of pair periods, where the key is an integer identifier and the value is a <see cref="PairPeriodTime"/> object.</returns>
     [CacheMaxAge(1, 0)]
     [HttpGet("PairPeriod")]
     public ActionResult<Dictionary<int, PairPeriodTime>> GetPairPeriod() => config.Value.ScheduleSettings!.PairPeriod.ConvertToDto();