feat(COMPONENT): Schematic to generate all system variables used for each component

### Feature Description

Hi,

I'd like to suggest creation of a schematic to generate font typography config, exactly like the one for theme_colors:

` ng generate @angular/material:theme-color`

It would be used like this:

` ng generate @angular/material:theme-typography`

It would take 2 font names as options, and generate a full configuration with default values, making customization way more simple for us.

Right now, we all have a lot of old classes like mat-body, mat-display- ... etc, and the old typography definition is no longer really useable and we should probably get rid of it asap.

Problem is people are lost, and documentation is way too shallow to be used like it is.
A simple generation of configuration including all necessary tokens for typography would make things very simple, without having to search all over the place for bribes of documentation about this or that.

I hope you'll consider this.

### Use Case

This is to help every single Angular M2 project to transition smoothly to Angular M3

Inizia esaminando lo schema theme-color esistente e la guida alla configurazione della tipografia per Angular Material. Definisci come il nuovo schema debba accettare due nomi di carattere e individua l’insieme completo dei token di tipografia e dei valori predefiniti che deve generare; il lavoro è completato quando il comando produce una configurazione completa utilizzabile per la migrazione ad Angular Material 3.

Scritto dal modello di indicizzazione a partire dal testo della issue.