go: add go modules (#3935)

* Add GO modules init command

Add command for initialising a new GO module. More about go modules: https://blog.golang.org/using-go-modules

Co-authored-by: Lucas Gabriel Schneider <casdpa@gmail.com>

pages/common/go.md

@@ -26,3 +26,7 @@
 - Compile and install the current package:
 
 `go install`
+
+- Initialize a new module in the current directory:
+
+`go mod init {{module_name}}`