docs: IDP configuration guide

[shyogesh-sw]

Issue #, if available: https://sim.amazon.com/issues/GALI-811

Description of changes: IDP topic has been rewritten and added to the SWB configuration guide.

Checklist:

• Have you successfully deployed to an AWS account with your changes?
• Have you written new tests for your core changes, as applicable?
• Have you successfully tested with your changes locally?
• If new dependencies have been added, have they been pinned to specific versions?
• Is this change also required on the AWS Solution version?
• Have you updated openapi.yaml if you made updates to API definition (including add, delete or update parameter and request data schema)?
• If you had to run manual tests, have you considered automating those tests by adding them to end-to-end tests?

AS review ticket id:

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[SanketD92]

LGTM

[codecov]

Codecov Report

Merging #569 (50470dc) into develop (9243d75) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #569   +/-   ##
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  Coverage    50.29%   50.29%           
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  Files          231      231           
  Lines        11770    11770           
  Branches      1855     1855           
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  Hits          5920     5920           
  Misses        5146     5146           
  Partials       704      704           

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