move .env to example folder

examples/.env.example

@@ -0,0 +1,29 @@
+SECRET_KEY=<application secret key>
+
+# i.e. an prosody server
+# create a nologin unix user `useradd -r -s /sbin/nologin <app_user>`
+LOGGING_XMPP_SERVER="example.com"
+LOGGING_XMPP_SENDER="<app_user>"
+LOGGING_XMPP_PASSWORD="<xmpp password for app_user>"
+LOGGING_XMPP_RECIPIENT="<admin>@example.com"
+LOGGING_XMPP_COMMAND="/usr/bin/sendxmpp"
+LOGGING_XMPP_USE_TLS=1
+
+# then create postrgresql role and database
+# DATABASE_URL="postgresql://<app_user>:<database password for user app_user>@localhost/<app_db>"
+# alternatively for unix socket connection
+DATABASE_URL="postgresql://<app_user>:<database password for user app_user>@/<app_db>?host=/var/run/postgresql"
+DATABASE_NAME="<app_db>"
+DATABASE_USER="<app_user>"
+DATABASE_PASSWORD="<database password for user app_user>"
+
+MAIL_SERVER='smtp.googlemail.com'
+MAIL_USE_TLS=1
+MAIL_PORT=587
+MAIL_USERNAME="<user>@gmail.com"
+MAIL_PASSWORD="<gmail application password>"
+
+MAIL_ADMINS="<admin>@gmail.com"
+EXTERNAL_URL="https://photo_app.example.com"
+
+PHOTO_URL="https://photos.example.com/"