Link to "Installing" page from "Quick Start" page is broken

[Ashvin-Ranjan]

The link on the Quick Start redirects to https://engineering.outreach.io/getting-started/installing instead of https://engineering.outreach.io/stencil/getting-started/installing, which is the correct page.

[jaredallard]

The joy of the complicated hugo template we're using :( Thanks for filling this!