[FEATURE]: Make a breaking changes list for v2.0.0

[Naarcha-AWS]

Is your feature request related to a problem?
Make a new breaking changes page for v2.0.0 features. Reference opensearch-project/OpenSearch#2480 for context.

See also breaking changes for 2.0 issue: opensearch-project/opensearch-clients#12

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A clear and concise description of what you want to happen.

What alternatives have you considered?
A clear and concise description of any alternative solutions or features you've considered.

Do you have any additional context?
Add any other context or screenshots about the feature request here.

[Naarcha-AWS]

Include: opensearch-project/OpenSearch#3023

[kavilla]

You can't directly migrate from versions less than 7.0 as indicated here: https://opensearch.org/docs/2.0/upgrade-to/upgrade-to/.

Reference: opensearch-project/OpenSearch#2936

[CEHENKLE]

@kavilla #2936 should be fixed now :)

[kavilla]

@kavilla #2936 should be fixed now :)

Does that mean user can migrate from 6.x to OpenSearch 2.0?