Add support for F3 View

Hello

I'm trying out 4.2.8 and notice that it doesn't include the usual F3 key to view the contents of a file. The only way to see what a file contains seems to be F4, which is used to edit a file.

If there's actually no support for read-only, I think it'd be useful to add.

Thank you.

Thanks for your post. This request is being tracked already.