Added translations directory to file tree

[fridde]

The description below the directory tree references the translation directory, which is missing in the tree.

[weaverryan]

@javiereguiluz Since symfony/recipes#253 was merged, this is valid, correct?

I'm not sure if it should be included, but it seems a little bit safer to show more directories here than less (so we can answer the question: "Hey, where do my translations go?")

[javiereguiluz]

Yes, this is correct. Should we add the remaining missing dirs?

assets/
bin/
  console
tests/
var/

[weaverryan]

Good idea! I just added the other dirs

[xabbuh]

Thank you @fridde.