feat: deploy via respec

[arnoweiss]

This PR creates a github-pages deployment for the DSP based on the respec tooling. The rendered webpage can be seen in the deployment of my fork [1]. As of this PR, all the source files are untouched and merely transferred directly.

This results in duplicate numbering, duplicate table of contents, broken references etc. I'd suggest to rework that cosmetically in subsequent PRs and limit this one to the mere infrastructure setup.

[1] https://arnoweiss.github.io/DataspaceProtocol/

[arnoweiss]

Fixed the schema redirects. Now the current subpaths match those from the deployed head. Examples: context.json from 2024-1 [1] and a schema from v0.8 [2].

[1]
https://arnoweiss.github.io/DataspaceProtocol/2024-1/common/schema/context.json
https://eclipse-dataspace-protocol-base.github.io/DataspaceProtocol/2024-1/common/schema/context.json

[2]
https://arnoweiss.github.io/DataspaceProtocol/v0.8/negotiation/message/schema/contract-schema.json
https://eclipse-dataspace-protocol-base.github.io/DataspaceProtocol/v0.8/negotiation/message/schema/contract-schema.json

[ssteinbuss]

LGTM. Thanks @arnoweiss good work.