bug#70876: Making join Info examples easier to test

[Dan Jacobson]

Today I tried to run these examples on
(info "(coreutils) Paired and unpaired lines")
it says:
 All examples below use the following two (pre-sorted) input files:

     $ cat file1                          $ cat file2
     a 1                                  a A
     b 2                                  c C

How about instead, something like
echo a 1 > file1
echo b 2 >> file1

echo a A > file2
echo c C >> file2

That way the user could create the files themselves without much hassle.
Just pipe that part of the page into the shell.

You can even still have the cats after the creation.
But please remember to just use one column.