updating readme for singularity runner

[vibhatha]

No description provided.

[github-actions]

MLCommons CLA bot:
Thank you for your submission, we really appreciate it. We ask that you sign our MLCommons CLA and be a member before we can accept your contribution. If you are interested in membership, please contact membership@mlcommons.org .
0 out of 1 committers have signed the MLCommons CLA.
❌ @vibhatha
_{You can retrigger this bot by commenting recheck in this Pull Request}

[laszewsk]

please can someone look at issue #22 which relates to the issue that the MLCommons CLA link is not working. This prevents contributors that have signed the CLA to have a check failed.
It is unclear what we have to do to fix this.