Non-KIT: Tutorials E2E & Umbrella docs — broken GitHub paths and missing site pages

### Affected source pages

- `./build/docs/tutorials/e2e/index.html:`
- `./build/docs/tutorials/e2e/boost/index.html:`
- `./build/docs/tutorials/e2e/connect/deployComponents/index.html:`
- `./build/docs/tutorials/e2e/inform/onboardingMaterial/index.html:`

### Broken links (full URLs)

From `./build/docs/tutorials/e2e/index.html:`

- `[404] https://eclipse-tractusx.github.io/developer`

From `./build/docs/tutorials/e2e/boost/index.html:`

- `[404] https://github.com/eclipse-tractusx/tractus-x-umbrella/blob/main/docs/user/guides/data-exchange.md`
- `[404] https://github.com/eclipse-tractusx/tractus-x-umbrella/blob/main/docs/user/guides/data-exchange/provide-data.md`
- `[404] https://github.com/eclipse-tractusx/tractus-x-umbrella/blob/main/docs/user/guides/data-exchange/consume-data.md`

From `./build/docs/tutorials/e2e/connect/deployComponents/index.html:`

- `[404] https://github.com/eclipse-tractusx/tractus-x-umbrella/blob/main/docs/user/installation/README.md`
- `[404] https://github.com/eclipse-tractusx/tractus-x-umbrella/blob/main/docs/user/network`
- `[404] https://github.com/eclipse-tractusx/tractus-x-umbrella/blob/main/docs/user/setup`

From `./build/docs/tutorials/e2e/inform/onboardingMaterial/index.html:`

- `[404] https://catena-x.net/en/benefits`
- `[404] https://catena-x.net/en/offers`
- `[404] https://catena-x.net/fileadmin/_online_media_/CX_Operating_Modelv2.1_final.pdf`
- `[404] https://catena-x.net/fileadmin/user_upload/04_Einfuehren_und_umsetzen/Onboarding/DataIntegrationPatterns_Guide_V1.1.pdf`