Fix indent in update-readme.go

[tksm]

This PR fixes the indent in update-readme.go as a code block.

Currently, make fmt will show the diff below.

diff --git a/hack/update-readme/update-readme.go b/hack/update-readme/update-readme.go
index 9526fdc..75e30a0 100644
--- a/hack/update-readme/update-readme.go
+++ b/hack/update-readme/update-readme.go
@@ -41,10 +41,13 @@ func main() {

 // GenerateFlagsMarkdownTable generates markdown table of flag list.
 // This function loads flag list and generates such as following text:
-//  flag            | default         | purpose
+//
+//     flag            | default         | purpose
+//
 // -----------------|-----------------|---------
-//  `--flag1`, `-f` |                 | This is flag1.
-//  `--flag2`       | `flag2-default` | This is flag2.
+//
+//     `--flag1`, `-f` |                 | This is flag1.
+//     `--flag2`       | `flag2-default` | This is flag2.
 func GenerateFlagsMarkdownTable() string {
        fs := pflag.NewFlagSet("", pflag.ExitOnError)
        o := cmd.NewOptions(genericclioptions.NewTestIOStreamsDiscard())

[rkmathi]

Thank you!