fix minor typo

[goshlanguage]

Hey friends, there's a smol typo in the README.

Thanks for your work on this project

[goshlanguage]

Is this still a valid input? I've tried to use this like so and got the following failure:

    steps:
      - name: Create k8s Kind Cluster
        uses: helm/kind-action@v1.2.0
        with:
          kubectl_version: "1.18.16"

Setup Kubernetes (1.18.16)
Unexpected input(s) 'kubectl_version', valid inputs are ['version', 'config', 'node_image', 'cluster_name', 'wait', 'log_level']

[davidkarlsen]

Is this still a valid input? I've tried to use this like so and got the following failure:

    steps:
      - name: Create k8s Kind Cluster
        uses: helm/kind-action@v1.2.0
        with:
          kubectl_version: "1.18.16"

Setup Kubernetes (1.18.16)
Unexpected input(s) 'kubectl_version', valid inputs are ['version', 'config', 'node_image', 'cluster_name', 'wait', 'log_level']

It hasn't been released yet, try the main version