Release 3.9.1 (elementary#1785)

* Release 3.9.1

* Update meson.build

* Update io.elementary.appcenter.appdata.xml.in

* Update io.elementary.appcenter.appdata.xml.in

Co-authored-by: Cassidy James Blaede <cassidy@elementary.io>

Release 3.9.0 (elementary#1772)

* Release 3.9.0

* Update meson.build

* Update io.elementary.appcenter.appdata.xml.in

Co-authored-by: Cassidy James Blaede <cassidy@elementary.io>

Release 3.8.2 (elementary#1734)

Release 3.8.1 (elementary#1724)

* Release 3.8.1

* Update meson.build

Co-authored-by: Cassidy James Blaede <cassidy@elementary.io>

Release 3.8.0 (elementary#1697)

* AppData: More details, bump to 3.8

* Update meson.build

* Update io.elementary.appcenter.appdata.xml.in

Co-authored-by: Danielle Foré <daniel@elementary.io>