Improve README to avoid copying

[Ngoc Dao]

README says:

If you did not proceed with step 2, copy the file misultin_hello_world.erl from the
Misultin examples directory to the directory where the .beam files compiled in step 1
are located, then CD to this directory and start an Erlang shell.

To avoid copying misultin_hello_world.erl, "-pa" can be used like this:

cd examples
erl -pa ../ebin
c(misultin_hello_world).

[Roberto Ostinelli]

fixed 0435014