Incorrect value for DNS TTL examples

[gravelpot]

Issue description

At:

documentation/source/content/partials/dns-propagation.md

Line 11 in 7d496ef

Every DNS record has a **Time To Live** (**TTL**) value, which specifies how long any DNS server should hold that record, before dropping it and asking for a new version from its upstream DNS provider. TTLs are usually set in seconds with a few common ones being `86400` (24 hours), `43200` (12 hours), `3600` (1 hour), and `500` (5 minutes).

the shortest TTL example shown says: 500 (5 minutes)

This is presumably meant to say 300 (5 minutes) (60 seconds * 5 minutes = 300 seconds), or perhaps 600 (10 minutes). A TTL of 500 seconds would be 8.3 minutes, which would be unusual.

The same value is repeated a few lines lower:

Lower the TTL values as low as allowed (usually 500) several days in advance at your DNS service manager.

Suggested Resolution

• Update to a correct value in both places, as appropriate.

[github-actions]

👋 @gravelpot
Thanks for opening your first issue here! @pantheon-systems/docs-admins is excited to review this!

If you like this project, please ⭐star⭐ our repo.

[stevector]

Thanks @gravelpot! I opened #9287