Improvement: front matter convention, add separators

[setop]

description

Having a front matter with --- separator before and after is more conventional and supported by many tools including GitHub. It is supported by Pelican.

Contributor Checklist

• [x] Check "Allow edit from maintainers" option in pull request so that additional changes can be pushed by the Bug Alert team if needed.
• [x] I have performed a self-review of my own code.
• [x] I have commented my code, particularly in hard-to-understand areas.
• [x] My changes generate no new warnings.
• [x] I have run Pelican locally to ensure my changes have not disrupted the look, feel, or functionality of the site.
• [x] I have checked my code and corrected any misspellings.
• [x] I have added a pull request description which details the nature of this change.

Leave the following intact, which notifies our volunteer team: @BugAlertDotOrg/volunteer-team

[sullivanmatt]

Pulled local and tested, also added separators for pages to @setop's branch. @mattlorimor please review and merge at will.

[sullivanmatt]

Thank you very much for your contribution @setop!