Update AWS maintenance docs

[reshmabidikar]

The following changes need to be done to the AWS maintenance docs:

1. Add ELB related maintenance steps to the multitier maintenance doc if required
2. Add information about SSL Certificate to the multitier maintenance doc if required
3. Add information about updating configuration parameters via the template to the cf maintenance doc

[reshmabidikar]

For 3/ - These are the notes from @vnandwana:

On CF dashboard, there is an option to update a stack. For more info, please check https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks.html. Also, customers can definitely SSH to an EC2 instance and update properties manually.

[vnandwana]

This PR (#584) adds the missing information about updating the CloudFormation stack.

@reshmabidikar, is there anything else pending for this task?

[reshmabidikar]

This PR (#584) adds the missing information about updating the CloudFormation stack.

@reshmabidikar, is there anything else pending for this task?

Yes, 1/ and 2/ above are still pending.

[vnandwana]

Got it. Let me know if there’s anything I need to do or if you need my help.