Fix shellcheck lint errors:

$ shellcheck init.bash

In init.bash line 3:
cd $(dirname $0)
   ^-----------^ SC2046: Quote this to prevent word splitting.
             ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean:
cd $(dirname "$0")

For more information:
  https://www.shellcheck.net/wiki/SC2046 -- Quote this to prevent word splitt...
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...

docs/examples/kustomize/init.bash

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 set -eux
-cd $(dirname $0)
+cd "$(dirname "$0")"
 
 umask 022
 mkdir -p base/site/