Template option to install snap packages

src/freedombone-template

 SHOW_ON_ABOUT=1
 database_type=''
 debian_packages=
+snap_packages=
 
 function show_help {
     echo ''
     echo $'  -o --onion [yes|no]                         Is this app only available on an onion address?'
     echo $'  -p --php [yes|no]                           Is this a PHP app?'
     echo $'     --packages [list of deb package names]   Debian packages to be installed'
+    echo $'     --snaps [list of snap package names]     Snap packages to be installed'
     echo $'  -s --daemon [yes|no]                        Add a daemon'
     echo $'  -d --database [mariadb|postgresql|mongodb]  Type of database'
     echo $'  -w --web [yes|no]                           Whether there is a web user interface (default is yes)'
             shift
             debian_packages="$1"
             ;;
+        --snaps|--snap)
+            shift
+            snap_packages="$1"
+            ;;
         *)
             # unknown option
             ;;
     echo ''
     echo "    remove_ddns_domain \"\$${app_name_upper}_DOMAIN_NAME\""
 fi
+if [ "$snap_packages" ]; then
+    echo ''
+    echo "    snap remove ${snap_packages}"
+fi
 echo '}'
 echo ''
 echo "function install_${app_name} {"
     echo "    apt-get -qy install ${debian_packages}"
     echo ''
 fi
+if [ "$snap_packages" ]; then
+    echo '    apt-get -qy install snapd'
+    echo "    snap install ${snap_packages}"
+    echo ''
+fi
 if [[ "$database_type" == "mariadb" || "$database_type" == "mysql" ]]; then
     echo '    install_mariadb'
     echo ''