Fix a shifted cell in the Prolog facts table

The files/3 fact in the table has its 3rd cell content continuing at the
next row, leading to wrong table format. This change fixes it by putting
back the text "A list of tuples ..." to the correct cell.

Link to the page:
https://gerrit-review.googlesource.com/Documentation/prolog-change-facts.html

Change-Id: I41c1e345f5739a64f5b4051193e778cfca6d5d7a
diff --git a/Documentation/prolog-change-facts.txt b/Documentation/prolog-change-facts.txt
index 51aef70..e5b4140 100644
--- a/Documentation/prolog-change-facts.txt
+++ b/Documentation/prolog-change-facts.txt
@@ -58,7 +58,7 @@
 
            |`files(file('a.txt', 'M', 'REGULAR')).'
 
-    |A list of tuples: The first argument is a file name of the current patchset.
+    A list of tuples: The first argument is a file name of the current patchset.
     The second argument is the modification type of this file, with the options being
     'A' for 'added', 'M' for 'modified', 'D' for 'deleted', 'R' for 'renamed', 'C' for
     'COPIED' and 'W' for 'rewrite'.