ci: publish crate docs to gh-pages

[xxchan]

I hereby agree to the terms of the Singularity Data, Inc. Contributor License Agreement.

What's changed and what's your intention?

Tried on my fork

https://github.com/xxchan/risingwave/actions/runs/3184942607/jobs/5193931735
https://xxchan.github.io/risingwave/

part of #4814

[codecov]

Codecov Report

Merging #5686 (da0e502) into main (1ee3732) will increase coverage by 0.01%.
The diff coverage is 70.58%.

@@            Coverage Diff             @@
##             main    #5686      +/-   ##
==========================================
+ Coverage   74.31%   74.32%   +0.01%     
==========================================
  Files         921      923       +2     
  Lines      144029   144284     +255     
==========================================
+ Hits       107033   107238     +205     
- Misses      36996    37046      +50     

Flag	Coverage Δ
rust	74.32% <70.58%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/batch/src/executor/mod.rs	72.30% <ø> (ø)
src/batch/src/lib.rs	100.00% <ø> (ø)
src/batch/src/task/broadcast_channel.rs	0.00% <0.00%> (ø)
src/batch/src/task/hash_shuffle_channel.rs	0.00% <0.00%> (ø)
src/common/src/array/data_chunk.rs	93.63% <ø> (ø)
src/common/src/util/chunk_coalesce.rs	97.98% <ø> (ø)
src/compute/src/server.rs	0.00% <0.00%> (ø)
src/frontend/src/optimizer/plan_node/mod.rs	98.27% <ø> (ø)
src/frontend/src/scheduler/task_context.rs	0.00% <0.00%> (ø)
src/stream/src/from_proto/global_simple_agg.rs	0.00% <0.00%> (ø)
... and 20 more

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