feat(DI-2719): add Signal IQ product documentation

[siddu1819]

Introduce client-facing docs for Signal IQ across AA, PDF, and bring-your-own FI data flows, and register the product in endpoints.

[github-actions]

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Review the corresponding checklist items for the action you performed and mark them done.

Edit an existing content (MDX) page

Checklist

• Review changes using the MDX preview option
• If the length of content >15000 chars, use the Content preview portal to view changes
• If a redirect is needed to the existing page, add a key, value pair in redirects.json

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Edit an existing API reference page

Checklist

• Use the Content preview portal to view changes
• API reference is in JSON format (OpenAPI or Swagger)

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Add a new content (MDX) page

Checklist

• Create a .mdx file with the path as its name in the content folder
• Add frontmatter with all the metadata
• Review the order of items in Sidebar using the Sidebar preview option
• Review changes using the MDX preview option
• If the length of content >15000 chars, use the Content preview portal to view changes
• Created a folder with the same name, if any children were to be added to the page
• Once all changes are done, update the menu items by using the Menu Items option
• Add a key, and value pair in redirects.json if you wish to have a redirect to the new page

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Add a new API reference page

Checklist

• Create a .json file with the product path as its name
• Create an api-reference.mdx file in the respective product folder inside content folder
• Add frontmatter with all the metadata
• Review the order of items in Sidebar using the Sidebar preview option
• Add API reference in JSON format (OpenAPI or Swagger) into created .json file.
• Used the Content preview portal to view changes
• Once all changes are done, update the menu items by using the Menu Items option