Implement "DO NOT EDIT" comment convention

Update all generated files with `go generate ./...`.

See golang/go#13560 for details.

example/mockpersonstore_test.go

@@ -1,8 +1,8 @@
-package example
-
-// AUTOGENERATED BY MOQ - DO NOT EDIT
+// Code generated by moq; DO NOT EDIT.
 // github.com/matryer/moq
 
+package example
+
 import (
 	"context"
 	"sync"
@@ -53,8 +53,8 @@ type PersonStoreMock struct {
 		Get []struct {
 			// Ctx is the ctx argument value.
 			Ctx context.Context
-			// Id is the id argument value.
-			Id string
+			// ID is the id argument value.
+			ID string
 		}
 	}
 }
@@ -105,10 +105,10 @@ func (mock *PersonStoreMock) Get(ctx context.Context, id string) (*Person, error
 	}
 	callInfo := struct {
 		Ctx context.Context
-		Id  string
+		ID  string
 	}{
 		Ctx: ctx,
-		Id:  id,
+		ID:  id,
 	}
 	lockPersonStoreMockGet.Lock()
 	mock.calls.Get = append(mock.calls.Get, callInfo)
@@ -121,11 +121,11 @@ func (mock *PersonStoreMock) Get(ctx context.Context, id string) (*Person, error
 //     len(mockedPersonStore.GetCalls())
 func (mock *PersonStoreMock) GetCalls() []struct {
 	Ctx context.Context
-	Id  string
+	ID  string
 } {
 	var calls []struct {
 		Ctx context.Context
-		Id  string
+		ID  string
 	}
 	lockPersonStoreMockGet.RLock()
 	calls = mock.calls.Get