Change "elderly" to "older adults"

[KameronKerger]

Describe the bug Reported issues with the word "Elderly" in the census demographic data. Change to "Older adults".

To Reproduce Steps to reproduce the behavior:

1. Go to 'explore the map / any census tract'
2. Click on 'age'
3. See error

Expected behavior Update string.

Screenshots If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context Add any other context about the problem here.

[KameronKerger]

add to content doc to track