Add missing VCS files to --exclude-vcs list

* src/tar.c (vcs_file_table): Add .gitmodules and .gitattributes
* doc/tar.texi: Update.

doc/tar.texi

@@ -7564,6 +7564,8 @@ As of version @value{VERSION}, the following files are excluded:
 @item @file{SCCS/}, and everything under it
 @item @file{.git/}, and everything under it
 @item @file{.gitignore}
+@item @file{.gitmodules}
+@item @file{.gitattributes}
 @item @file{.cvsignore}
 @item @file{.svn/}, and everything under it
 @item @file{.arch-ids/}, and everything under it

src/tar.c

@@ -953,6 +953,8 @@ static char const * const vcs_file_table[] = {
   /* git: */
   ".git",
   ".gitignore",
+  ".gitattributes",
+  ".gitmodules",
   /* Arch: */
   ".arch-ids",
   "{arch}",