Add initial Debian packaging files for G1nkgo application (that was not commited)

debian/.debhelper/generated/ginkgo/installed-by-dh_install

+./build/linux/x64/release/bundle/ginkgo
+./build/linux/x64/release/bundle/data
+./build/linux/x64/release/bundle/lib

debian/debian.yaml

+flutter_app: 
+  command: ginkgo
+  arch: x64
+  parent: /usr/local/lib
+  nonInteractive: false
+
+control:
+  Package: g1nkgo
+  Version: 1.3.1
+  Architecture: amd64
+  Priority: optional
+  Depends:
+  Maintainer: Vicente J. Ruiz Jurado <vjrj@comunes.org>
+  Description: G1nkgo - A digital wallet based on Duniter for the G1 currency

debian/gui/g1nkgo.desktop

+[Desktop Entry]
+Version=1.0
+Name=g1nkgo
+GenericName=g1nkgo
+Comment=G1nkgo - A digital wallet based on Duniter for the G1 currency
+Terminal=false
+Type=Application
+Categories=Utility
+Keywords=Flutter;duniter;g1
+#Exec=/usr/local/lib/g1nkgo/ginkgo

debian/scripts/preinst

+#!/bin/sh
+
+#######################################################
+#
+# Add here the commands to be excuted before the package
+# has been installed
+#
+
+set -e
+
+#DEBHELPER#
+
+echo Installing g1nkgo