feat: Add link to component implementation in API doc

**Is your feature request related to a problem? Please describe.**
I often need to check the source code of components to discover how they work, to fix bugs etc. Right now I have to manually open GitHub and navigate to the component.

**Describe the solution you'd like**
Add a direct link to the component implementation in `ionic-team/ionic-framework` (folder or tsx), maybe at the end of the page next to the `Contribute >` button.

**Describe alternatives you've considered**
Navigating manually each time.