Fix typo in IEndpointSelectorPolicy documentation (#64403)

Author: voroninp

src/Http/Routing/src/Matching/IEndpointSelectorPolicy.cs

@@ -6,7 +6,7 @@
 namespace Microsoft.AspNetCore.Routing.Matching;
 
 /// <summary>
-/// A <see cref="MatcherPolicy"/> interface that can implemented to filter endpoints
+/// A <see cref="MatcherPolicy"/> interface that can be implemented to filter endpoints
 /// in a <see cref="CandidateSet"/>. Implementations of <see cref="IEndpointSelectorPolicy"/> must
 /// inherit from <see cref="MatcherPolicy"/> and should be registered in
 /// the dependency injection container as singleton services of type <see cref="MatcherPolicy"/>.