Fix misleading XML documentation for pairwise functions (#18587)

Author: Copilot

src/FSharp.Core/array.fsi

@@ -1919,8 +1919,9 @@ module Array =
     [<CompiledName("OfSeq")>]
     val ofSeq: source: seq<'T> -> 'T array
 
-    /// <summary>Returns an array of each element in the input array and its predecessor, with the
-    /// exception of the first element which is only returned as the predecessor of the second element.</summary>
+    /// <summary>Returns an array of each element in the input array paired with its predecessor, with the
+    /// exception of the first element which is only returned as the predecessor of the second element.
+    /// The predecessor comes first in the returned pairs.</summary>
     ///
     /// <param name="array">The input array.</param>
     ///

src/FSharp.Core/list.fsi

@@ -1613,8 +1613,9 @@ module List =
     [<CompiledName("OfSeq")>]
     val ofSeq: source:seq<'T> -> 'T list
 
-    /// <summary>Returns a list of each element in the input list and its predecessor, with the
-    /// exception of the first element which is only returned as the predecessor of the second element.</summary>
+    /// <summary>Returns a list of each element in the input list paired with its predecessor, with the
+    /// exception of the first element which is only returned as the predecessor of the second element.
+    /// The predecessor comes first in the returned pairs.</summary>
     ///
     /// <param name="list">The input list.</param>
     ///

src/FSharp.Core/seq.fsi

@@ -1852,8 +1852,9 @@ module Seq =
     [<CompiledName("OfList")>]
     val ofList: source: 'T list -> seq<'T>
 
-    /// <summary>Returns a sequence of each element in the input sequence and its predecessor, with the
-    /// exception of the first element which is only returned as the predecessor of the second element.</summary>
+    /// <summary>Returns a sequence of each element in the input sequence paired with its predecessor, with the
+    /// exception of the first element which is only returned as the predecessor of the second element.
+    /// The predecessor comes first in the returned pairs.</summary>
     ///
     /// <param name="source">The input sequence.</param>
     ///