message: Fix install instructions: make `$d` absolute
diff: # Setup
  -TODO: vendor some of this, or otherwise reduce the external
  -dependencies.
  -
  ```
  # NB: need submodules
  -d=kubeapps-manifest
  +d=$PWD/kubeapps-manifest
  git clone --recurse-submodules https://github.com/kubeapps/manifest $d
  # Install kubecfg somewhere in $PATH
  