fix(uptime): Add heading and description to overview

[evanpurkhiser]

[codecov]

❌ 1 Tests Failed:

Tests completed	Failed	Passed	Skipped
8576	1	8575	3

View the top 1 failed test(s) by shortest run time

Uptime Overview renders

Stack Traces | 0.678s run time

Error: expect(element).toHaveTextContent()

Expected element to have text content:
  Backend
Received:
  Uptime Monitors
    at Object.<anonymous> (.../uptime/views/overview.spec.tsx:88:9)
    at runNextTicks (node:internal/process/task_queues:65:5)
    at processTimers (node:internal/timers:526:9)

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