New > Elixir File should underscore file name

[KronicDeth]

The current version of New > Elixir File, as so nicely provided by @abaire, doesn't differentiate between the File name and the Module name, so if you enter a Module name of Foo, the file is named Foo.ex, but Elixir convention is for the file name to be lowercase and underscored, so ExUnit Module name becomes ex_unit.ex. I tried debugging the Action and I'm not sure if using the CreateFileFromTemplateAction allows us to have a different File name and Module name since there is only one NAME attribute passed into the template. I may be possible to look at how the Package and Class creation actions work for Java and see if its possible to set the Module name as the PACKAGE_NAME or CLASS_NAME attribute and have the file name derived from that for the NAME attribute.