add 4 new Henry M Jackson Foundation jobs

[crd477]

Description

Add 4 new Henry M Jackson Foundation jobs from Google Form responses 527, 528, 529, 530

Checklist:

• [x] I have previewed changes locally or with CircleCI (runs when PR is created)
• [ ] 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.

[crd477]

Preview here.

[crd477]

Previews for the other changed pages: https://output.circle-artifacts.com/output/job/ca6ba54c-c808-4be3-85b4-73ab7084470e/artifacts/0/usrse.github.io/2021-11-12-sc-candidates/index.html https://output.circle-artifacts.com/output/job/ca6ba54c-c808-4be3-85b4-73ab7084470e/artifacts/0/usrse.github.io/2021-10-27-newsletter/index.html

[danielskatz]

thanks @crd477 !