Fix typos, broken links and missing images on committee and helpdesk …

[cliodhnaharrison]

…pages

Closes #

Description

Checklist

I confirm that before I submitted this pull request I did the following:

• [X ] Confirmed that no other open PRs address this issue.
• [X ] Checked out the latest version of the site.
• [ ] Ran yarn start and confirmed that there were no issues.
• [ ] Annotated my code with the relevant license information (if applicable).