Implement "card" variant for Button component

[mkrause]

Resolves #120

GritQL migration script used for variant → kind change.

engine marzano(0.1)
language js

pattern element($component_name, $props, $children) {
    or {
        jsx_element(open_tag=jsx_opening_element(name=$tag, attribute=$props), close_tag=jsx_closing_element(name=$close_tag), children=$children),
        jsx_self_closing_element(name=$tag, attribute=$props),
    } where {
        $close_tag <: maybe $tag, // Does not always exist (may be a self-closing element)
        $tag <: or {
            $component_name,
            member_expression(object=$component_name), // `$component_name.$_`
            member_expression(object=member_expression(object=$component_name)), // `$component_name.$_.$_`
        },
    },
}

bubble element(`Button`, $props) where {
    $props <: maybe contains or {
        jsx_attribute(name="variant" => `kind`),
    }
}

[nighto]

LGTM 🚀