Use the OpenAPI's title for rendered HTML pages

[ZakCodes]

When using the CLI, if you don't explicitly provide a title using the --title option, the title of the outputed page is ReDoc Documentation.

Instead of using the default title, ReDoc could use the title provided by the OpenAPI document that is being rendered. In the OpenAPI standard, there's an info object in the root of the document with a title property that could be used. This property is already used by ReDoc cli at the very beginning of the rendered HTML page.

I would understand if you would like to keep it like that for advertising, but I think it's really annoying because I need to copy the title from my OpenAPI document and pass it to ReDoc cli, so whenever I want to change a title, I need to remember to change it in my rendering scripts.
I think the title of an HTML document isn't what's going to give you the most publicity since the users can't even click on it. Therefore, if you really want to advertise this tool, you would be better off adding a link to ReDoc right under the title in the HTML body where people can click on, just like you did in the left sidebar.