Backup: change config format to toml

With support of multiple config values

files/backups/config.template.toml

@@ -0,0 +1,17 @@
+roots = [
+    "{{ application_dir }}"
+]
+
+[storage.yandex]
+type = "restic"
+restic_repository = "{{ restic_repository }}"
+restic_password = "{{ restic_password }}"
+aws_access_key_id = "{{ restic_s3_access_key }}"
+aws_secret_access_key = "{{ restic_s3_access_secret }}"
+aws_default_region = "{{ restic_s3_region }}"
+
+[notifications.telegram]
+type = "telegram"
+telegram_bot_token = "{{ notifications_tg_bot_token }}"
+telegram_chat_id = "{{ notifications_tg_chat_id }}"
+notifications_name = "{{ notifications_name }}"