That link of course is a technical answer to the question, and if you are looking for the jar for a technical reason ought to give you a hint of what to do/ask next.
However most users I recommend this: instead of poking around the file system try:
* Running the installer
* Then the launcher
* Then launching a profile with that version of forge.
Did it not launch? Did it launch as vanilla? Is there an error? Or did the correct version of Minecraft+Forge launch as expected?
(Note looking at the versions directory is not in here as in normal operation there is no need for you to look.. although if its missing from the versions list in the launcher profile editor there is a problem)