BCDA-7867: Add 429 recommendations

[alex-dzeda]

🎫 Ticket

https://jira.cms.gov/browse/BCDA-7867

🛠 Changes

Added best practices section to "Building Your Application" page, with first best practice being handling 429 status codes.

ℹ️ Context for reviewers

BCDA has two 429 mechanisms, neither of which currently shows recommendations on how to avoid / handle them. By clearly outlining how we recommend clients handle them, we can improve the quality of the BCDA experience and decrease the number of posts that require triaging in the google group.

✅ Acceptance Validation

🔒 Security Implications

• This PR adds a new software dependency or dependencies.
• This PR modifies or invalidates one or more of our security controls.
• This PR stores or transmits data that was not stored or transmitted before.
• This PR requires additional review of its security implications for other reasons.

If any security implications apply, add Jason Ashbaugh (GitHub username: StewGoin) as a reviewer and do not merge this PR without his approval.

[greg-pf]

Suggest adding something along the lines of See our [best practices](#handling-429-error) for more information on handling 429 errors. to the following section

bcda-static-site/_includes/build/requesting_data_runouts.html

Lines 64 to 66 in 01f86bb

	<p>
	If you're already requesting data from one endpoint and try to request data from that endpoint again while the first request is processing, you'll receive a 429 Too Many Requests error.
	</p>

[greg-pf]

Requesting review from Jennifer via slack

[alex-dzeda]

Suggest adding something along the lines of See our [best practices](#handling-429-error) for more information on handling 429 errors. to the following section

bcda-static-site/_includes/build/requesting_data_runouts.html

Lines 64 to 66 in 01f86bb

	<p>
	If you're already requesting data from one endpoint and try to request data from that endpoint again while the first request is processing, you'll receive a 429 Too Many Requests error.
	</p>

Updated!

[laurenkrugen-navapbc]

Thanks for adding this Alex! I will approve; do we also have approval from someone on the content team?

[greg-pf]

Sharing Jennifer's review and content edits

[greg-pf]