Please document `app.exe_path` and `win.class`

[Enyium]

• Please document app.exe_path and win.class on this page.
  • app.exe_path can be used, if the .exe name doesn't reveal the app's identity, but only the name of an ancestor directory.
  • win.class is sometimes a great way to be sure about the window's identity, if the app provides useful information - even being independent from app translations, in contrast to the title alone.
• There's also win.title as opposed to the already documented title. It would be nice to learn the difference.
• I think, this page should link to this page, so that one can easily get to the list of possible constraints when writing/editing .py code instead of .talon code.