Implement Try It Button if users Visit Voice Fill Directly (not from Add-on)

[johngruen]

Since we're putting this thing on the web it will be publicly discoverable, we will want to handle the case of someone navigating to voice fill directly...

We will need to add a view that gives users the option to Try Voice Fill.

See this document for the flow.

[ChenMorpheus]

@johngruen I might need more context here for this ticket and #218 since I don't know the final solution to the issue of microphone permissions. Based on the flow you provided, it seems that VF 2.0 will be a stand-alone site so that users can only grant permission once, right? Besides, "users navigate from the web" means users would find this screen by keyword searching?