This is breaking the build in `electron/electronjs.org-new` and will most likely not work when clicking the "Fiddle" button. Rel: https://github.com/electron/electronjs.org-new/pull/65
* docs: modernize protocol-handler docs * docs: iadd contextIsolation * docs: add guide for launch-app-from-URL-in-other-app * docs: address comments * chore: fix brackets * chore: add escaped brackets