Add XML documentation to generic FragmentManager helper methods

src/Mono.Android/Android.App/FragmentManager.cs

@@ -5,6 +5,17 @@
 #if ANDROID_11
 namespace Android.App {
 	public partial class FragmentManager {
+		/// <summary>
+		/// Finds a <see cref="Fragment"/> that was identified by the given id, either when
+		/// inflated from XML or as the container id when added in a transaction, and returns
+		/// it cast to <typeparamref name="T"/>.
+		/// </summary>
+		/// <typeparam name="T">The <see cref="Fragment"/> type to cast the result to.</typeparam>
+		/// <param name="id">The resource id or container id used to identify the fragment.</param>
+		/// <returns>
+		/// The matching fragment cast to <typeparamref name="T"/>, or <see langword="null"/>
+		/// if no matching fragment exists.
+		/// </returns>
 		public T? FindFragmentById<
 				[DynamicallyAccessedMembers (Constructors)]
 				T
@@ -14,6 +25,17 @@ public T? FindFragmentById<
 			return FindFragmentById (id).JavaCast<T> ();
 		}
 
+		/// <summary>
+		/// Finds a <see cref="Fragment"/> that was identified by the given tag, either when
+		/// inflated from XML or as supplied when added in a transaction, and returns it cast
+		/// to <typeparamref name="T"/>.
+		/// </summary>
+		/// <typeparam name="T">The <see cref="Fragment"/> type to cast the result to.</typeparam>
+		/// <param name="tag">The tag used to identify the fragment.</param>
+		/// <returns>
+		/// The matching fragment cast to <typeparamref name="T"/>, or <see langword="null"/>
+		/// if no matching fragment exists.
+		/// </returns>
 		public T? FindFragmentByTag<
 				[DynamicallyAccessedMembers (Constructors)]
 				T
@@ -23,6 +45,18 @@ public T? FindFragmentByTag<
 			return FindFragmentByTag (tag).JavaCast<T> ();
 		}
 
+		/// <summary>
+		/// Retrieves the current <see cref="Fragment"/> instance for a reference previously
+		/// placed in <paramref name="bundle"/> with <c>PutFragment</c>, and returns it cast
+		/// to <typeparamref name="T"/>.
+		/// </summary>
+		/// <typeparam name="T">The <see cref="Fragment"/> type to cast the result to.</typeparam>
+		/// <param name="bundle">The bundle in which the fragment reference was stored.</param>
+		/// <param name="key">The name of the entry in the bundle.</param>
+		/// <returns>
+		/// The referenced fragment cast to <typeparamref name="T"/>, or <see langword="null"/>
+		/// if no fragment is associated with the given key.
+		/// </returns>
 		public T? GetFragment<
 				[DynamicallyAccessedMembers (Constructors)]
 				T