Generate Rust docs and embed them in Docusaurus

[SebastienGllmt]

Right now we don't have any docs generated for the Rust code. It could be useful to generate them and add them to Docusaurus as well

[SebastienGllmt]

Although this is possible by adding to docs/package.json the following command

"bin:rustdoc": "cargo doc --manifest-path ../indexer/tasks/Cargo.toml --no-deps --target-dir ../indexer/tasks/target && rm -rf ./bin/rust && cp -r ../indexer/tasks/target/doc ./static/rust",

The resulting docs are not readable because of all the automatically generated things from the macro so probably this is not helpful.