Project structure refactor:

- Change package name general_server to gateway
- Changing the structure of directories and packages
- Adding vendor to the project

vendor/github.com/go-viper/mapstructure/v2/.gitignore

@@ -0,0 +1,6 @@
+/.devenv/
+/.direnv/
+/.pre-commit-config.yaml
+/bin/
+/build/
+/var/