v2 to v3 upgrade guide

Take a look at our carbon-angular-starter for a quickstart on v3

Additions

• @carbon/icons-angular ^10.1.0 is now a peer dependency

Changes

• Default header styles are no longer supported, you must define you own heading/body styles using typesets

// Example
h1 {
    @include type-style('productive-heading-05');
}

Removals

• Remove the experimental feature flag