[Analytics] Add link to documentation for Pinpoint service imposed limits

[mutablealligator]

Describe the bug

Amazon Pinpoint has several limits imposed by the service on the endpoints and events. However the iOS and Android SDK documentation does not have links to those documentation.

To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
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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
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[mutablealligator]

PR #727 addresses this issue.