Small improvements to a couple of pages of the starting guides

[siiky]

No description provided.

[stjhimy]

Also note the controller name (HelloController) and the view name (HelloHTML) and their respective files, hello_controller.ex and hello_html.ex all follow the same naming convention. and are named after each other. You could name the directory anything you want, as long as you update the embed_templates setting accordingly, but it's best to follow conventions.

Shouldn't there be a capital A? ... convention. And are named.... ?

[siiky]

It's a comma, as it was originally (see c8c6cea). A full sentence to say "And are named after each other." by itself would be a little weird in my opinion.