Merge pull request #1311 from JohannesPfeifer/filename_manual

Manual: add that if several files differ only by the extension, the f…

doc/dynare.texi

@@ -4970,6 +4970,11 @@ required for the @file{.csv} and @file{.xlsx} formats and the @file{.xls} file
 extension is not supported). Note that the base name (@i{i.e.} without
 extension) of the datafile has to be different from the base name of the model
 file.
+If there are several files named @code{FILENAME}, but with different file endings,
+the file name must be included in quoted strings and provide the file ending like
+@example
+@code{estimation(datafile='../fsdat_simul.mat',...)}
+@end example
 
 @item dirname = @var{FILENAME}
 Directory in which to store @code{estimation} output. To pass a