content: Google Fonts integration / local hosting

### URL

https://ionicframework.com/docs/v3/api/components/typography/Typography/

### Issue Description

Ionic Framework uses a Google Font (`Roboto`), however, the default build doesn't include the font.

It would be nice if the documentation also explains how to host the Google Fonts used by Ionic (and other ones)
(local hosting would be important for GDPR compliance).

What can be used for this? A webpack loader? An ionic script?

Start with the Typography documentation at the linked URL and locate the corresponding source page in the ionic-docs repository; no source file is named in the issue. Determine the supported local-hosting guidance for Roboto and other Google Fonts, then document the approach and its GDPR implications in the relevant documentation.

Written by the indexing model from the issue text.