fix: fixing standards headings and math standards in EDU Lesson template

[stephiescastle]

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Description

Addresses feedback:

• https://github.com/nasa-jpl/www/issues/99#issuecomment-2338655736

Fixes:

• Updates headings for each Standards type
• Fixes type for math standards (ccss_math vs ccss_maths)

Instructions to test

Tested in the following environments/browsers:

Operating System

• macOS
• iOS
• iPadOS
• Windows

Browser

• Chrome
• Firefox ESR
• Firefox
• Safari
• Edge

[jamesray]