Bugfix/routing regex (#1738)

* Fix the regex route in Startup.cs

* Fix the regex route in routing.rst

aspnet/fundamentals/routing.rst

@@ -353,7 +353,7 @@ The following table demonstrates some route constraints and their expected behav
     - Steve
     - String must consist of alphabetical characters.
   * - ``regex(expression)``
-    - {ssn:regex(\d{3}-\d{2}-\d{4})}
+    - {ssn:regex(^\d{3}-\d{2}-\d{4}$)}
     - 123-45-6789
     - String must match the provided regular expression.
   * - ``required``

aspnet/fundamentals/routing/sample/RoutingSample/Startup.cs

@@ -27,7 +27,7 @@ namespace RoutingSample
 
             routeBuilder.MapRoute(
                 "Track Package Route",
-                "package/{operation:regex(track|create|detonate)}/{id:int}");
+                "package/{operation:regex(^track|create|detonate$)}/{id:int}");
 
             routeBuilder.MapGet("hello/{name}", context =>
             {