docs: Flagsmith Concepts section

[guiwrite]

Thanks for submitting a PR! Please check the boxes below:

• I have added information to docs/ if required so people know about the feature!
• I have filled in the "Changes" section below?
• I have filled in the "How did you test this code" section below?
• I have used a Conventional Commit title for this Pull Request

Changes

• Add Data Model explanation page
• Add Platform Architecture explanation page
• Add Identities explanation page
• Add Segments explanation page
• Add Segment Rule Operators reference
• Add Targeting and Rollouts explanation page

How did you test this code?

Please describe.

[vercel]

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Name	Status	Preview	Comments	Updated (UTC)
docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Aug 8, 2025 11:09am

2 Skipped Deployments

Name	Status	Preview	Comments	Updated (UTC)
flagsmith-frontend-preview	⬜️ Ignored (Inspect)	Visit Preview		Aug 8, 2025 11:09am
flagsmith-frontend-staging	⬜️ Ignored (Inspect)	Visit Preview		Aug 8, 2025 11:09am

[vercel]

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[matthewelwell]

@guiwrite the preview build is failing on this one because of some broken links as per the below error message. Are you able to please resolve them before we review this?

Exhaustive list of all broken links found:
  - Broken link on source page path = /flagsmith-concepts/identities:
     -> linking to segments.md (resolved as: /flagsmith-concepts/segments.md)
  - Broken link on source page path = /flagsmith-concepts/segments/:
     -> linking to managing-identities.md#identity-traits (resolved as: /flagsmith-concepts/segments/managing-identities.md#identity-traits)
     -> linking to managing-identities.md#identity-overrides (resolved as: /flagsmith-concepts/segments/managing-identities.md#identity-overrides)
     -> linking to managing-features.md#multi-variate-flags (resolved as: /flagsmith-concepts/segments/managing-features.md#multi-variate-flags)
     -> linking to /flagsmith-concepts/targeting-and-rollouts.md
  
      at throwError (/vercel/path0/docs/node_modules/@docusaurus/logger/lib/logger.js:80:11)
      at reportBrokenLinks (/vercel/path0/docs/node_modules/@docusaurus/core/lib/server/brokenLinks.js:250:47)
      at handleBrokenLinks (/vercel/path0/docs/node_modules/@docusaurus/core/lib/server/brokenLinks.js:282:5)
      at executeBrokenLinksCheck (/vercel/path0/docs/node_modules/@docusaurus/core/lib/commands/build/buildLocale.js:91:47)
      at /vercel/path0/docs/node_modules/@docusaurus/core/lib/commands/build/buildLocale.js:70:67
      at Object.async (/vercel/path0/docs/node_modules/@docusaurus/logger/lib/perfLogger.js:42:47)
      at buildLocale (/vercel/path0/docs/node_modules/@docusaurus/core/lib/commands/build/buildLocale.js:70:31)
      at async runBuildLocaleTask (/vercel/path0/docs/node_modules/@docusaurus/core/lib/commands/build/build.js:93:5)
      at async /vercel/path0/docs/node_modules/@docusaurus/core/lib/commands/build/build.js:74:13
      at async tryToBuildLocale (/vercel/path0/docs/node_modules/@docusaurus/core/lib/commands/build/build.js:70:9)
      at async /vercel/path0/docs/node_modules/@docusaurus/core/lib/commands/build/build.js:34:9
      at async mapAsyncSequential (/vercel/path0/docs/node_modules/@docusaurus/utils/lib/jsUtils.js:21:24)
      at async Command.build (/vercel/path0/docs/node_modules/@docusaurus/core/lib/commands/build/build.js:33:5)
      at async Promise.all (index 0)
      at async runCLI (/vercel/path0/docs/node_modules/@docusaurus/core/lib/commands/cli.js:56:5)
      at async file:///vercel/path0/docs/node_modules/@docusaurus/core/bin/docusaurus.mjs:44:3

[robertnorrie]

I think we're good to go on this section now. I've gone through the added segments and the structure and content all look good.