fix: adjustments to floating images and unordered list markers

[stephiescastle]

Checklist

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Description

Addresses feedback:

• https://github.com/nasa-jpl/www/issues/217#issuecomment-2347088724
• https://github.com/nasa-jpl/www/issues/217#issuecomment-2349369871

Changes:

• Switched from using :before to :marker and using an emdash as the list marker. This allows for correct position of the marker alongside floating images
• Updated BlockKeyPoints to match
• Adjusted margins for content with Student Project steps

Instructions to test

1. make vue-storybook
2. BlockText story with richtext media: http://localhost:6006/?path=/story/components-blocks-blocktext--rich-text-media&globals=theme:ThemeEdu
3. BlockText story with subsequent floating images: http://localhost:6006/?path=/story/components-blocks-blocktext--subsequent-floating-images&globals=theme:ThemeEdu
4. Student Projects story: http://localhost:6006/?path=/story/templates-edu-pageedustudentproject--base-story&globals=theme:ThemeEdu
5. Key points story: http://localhost:6006/?path=/story/components-blocks-blockkeypoints--base-story

Tested in the following environments/browsers:

Operating System

• macOS
• iOS
• iPadOS
• Windows

Browser

• Chrome
• Firefox ESR
• Firefox
• Safari
• Edge