pub fn index_view_str(mut self, val: &str) -> Self {
        self.index_view = val.to_string();
        self
    }
Sets the index view as a string. This should be used if you're using an
`index.html` file or the like.

Note: if possible, you should switch to using `.index_view()`, which
uses a Sycamore view rather than an HTML string.
packages/perseus/src/init.rs