Document the Calendar API along with support for auth.

Middleware/Authen.cs

@@ -154,6 +154,7 @@ namespace CarCareTracker.Middleware
                 if (value.ToString().ToLower() == "api")
                 {
                     Response.StatusCode = 401;
+                    Response.Headers.Append("WWW-Authenticate", "Basic");
                     return Task.CompletedTask;
                 }
             }

Views/API/Index.cshtml

@@ -578,6 +578,20 @@
         vehicleId - Id of Vehicle
     </div>
 </div>
+<div class="row api-method">
+    <div class="col-1">
+        <span class="badge bg-success">GET</span>
+    </div>
+    <div class="col-5 copyable">
+        <code>/api/calendar</code>
+    </div>
+    <div class="col-3">
+        Returns reminder calendar in ICS format
+    </div>
+    <div class="col-3">
+        No Params
+    </div>
+</div>
 <div class="row api-method">
     <div class="col-1">
         <span class="badge bg-primary">POST</span>