Update css headers to closer resemble the corebook

Intent

Inspired by Case's CSS I've updated the HTML Headers to more closely resemble the Core Book Styles.

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• This is meant for a hotfix
• This is meant for the next release (see milestone)
• This needs more reviewers than normal; there may be controversy or high complexity
• This intentionally introduces regressions that will be addressed later
• There is/will be documentation changes on the wiki
• Please do not send commits here without coordinating closely with the owner
• This is a Build System change

Related Issues

• N/A

Steps to Test

1. Checkout / Build / Load
2. Create a Journal
3. Add A Journal Page
4. Create a Header of each type {h1..h6}
5. See new styles