docs: define go import convention

Add a developer doc that explains how to arrange imports so that
when new imports are added, unnecessary changes in import space
are avoided.

docs/development.md

@@ -206,3 +206,30 @@ please add a ref tag comment:
 please refer to the swagger specification of Kubernetes for any particular release. For e.g
 In Kubernetes 1.7, the reference tag for deployment is
 `io.k8s.kubernetes.pkg.apis.apps.v1beta1.DeploymentSpec`.
+
+### golang dependency import conventions
+
+imports MUST be arranged in three sections, separated by empty line.
+
+```go
+stdlib
+kedge
+thirdparty
+```
+
+for e.g.
+
+```go
+    "fmt"
+    "io"
+    "os/exec"
+
+    pkgcmd "github.com/kedgeproject/kedge/pkg/cmd"
+    "github.com/kedgeproject/kedge/pkg/spec"
+
+    "github.com/ghodss/yaml"
+    "github.com/pkg/errors"
+```
+
+And once arranged in such sections let go tooling take care of sorting the
+sequence of imports for you.