Added next E&T talk

[JeffCarver]

Description

Checklist:

• [x] I have previewed changes locally or with CircleCI (runs when PR is created)
• [x] I have completed any content reviews, such as getting input from relevant working groups. If no, please note this and wait to post the PR to the #website channel until the content has been settled.

When you are ready for a technical review/merge, post the for the link for the PR in the US-RSE Slack (#website) to ask for reviewers.

[JeffCarver]

Preview: https://output.circle-artifacts.com/output/job/1d8b9ed5-50a8-4cd7-877b-17a8c6c665c8/artifacts/0/usrse.github.io/wg/education_training/seminar_series/index.html

[sanyatonwu]

Looks good to me. I can squash and merge.