`<!snake_case>` components

[maciejhirsz]

• BREAKING Instead of PascalCase component functions now must be named in idiomatic snake_case.
• BREAKING Invoking components in the view! macro now requires an ! before the name.
• BREAKING Moving towards new versions of Trunk, it's no longer required (in fact it will break things!) to use the custom pattern_script in Trunk.toml.
• #[component] functions can be called as regular functions.
• It's no longer necessary to self-close component tags with a tailing />. All component invocations are assumed to not have any children unless an explicit closing tag (</!name>) is present.

Old:

#[component]
fn Foo() -> impl View { ... }

view! {
    <Foo />
}

New:

#[component]
fn foo() -> impl View { ... }

view! {
    <!foo>
}