Review and update Traffic Manager rule docs

[BernieWhite]

Review and update rule documentation with template and bicep examples.

Find documentation here: https://azure.github.io/PSRule.Rules.Azure/en/rules/resource/#traffic-manager

Find source here: https://github.com/Azure/PSRule.Rules.Azure/tree/main/docs/en/rules

An example of documentation that is representative of ideal documentation is Cognitive Services: https://azure.github.io/PSRule.Rules.Azure/en/rules/resource/#cognitive-services