docs: Add docs for Go feature server

[felixwang9817]

Signed-off-by: Felix Wang wangfelix98@gmail.com

What this PR does / why we need it: This PR adds docs for the Go feature server.

Which issue(s) this PR fixes:

Fixes #

[codecov-commenter]

Codecov Report

Merging #2540 (fbf4cca) into master (9025280) will decrease coverage by 0.12%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2540      +/-   ##
==========================================
- Coverage   81.65%   81.52%   -0.13%     
==========================================
  Files         141      141              
  Lines       12011    12011              
==========================================
- Hits         9807     9792      -15     
- Misses       2204     2219      +15     

Flag	Coverage Δ
integrationtests	73.47% <100.00%> (-0.48%)	⬇️
unittests	57.60% <100.00%> (ø)

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

Impacted Files	Coverage Δ
...ts/integration/feature_repos/repo_configuration.py	89.59% <ø> (ø)
sdk/python/feast/feature_store.py	89.34% <100.00%> (ø)
sdk/python/feast/repo_config.py	89.52% <100.00%> (ø)
...tion/feature_repos/integration_test_repo_config.py	92.30% <100.00%> (ø)
sdk/python/feast/wait.py	58.82% <0.00%> (-35.30%)	⬇️
sdk/python/tests/utils/online_read_write_test.py	93.54% <0.00%> (-6.46%)	⬇️
.../integration/online_store/test_online_retrieval.py	96.84% <0.00%> (-3.16%)	⬇️
...ython/feast/embedded_go/online_features_service.py	96.42% <0.00%> (-0.90%)	⬇️
.../integration/online_store/test_universal_online.py	92.59% <0.00%> (-0.86%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 9025280...fbf4cca. Read the comment docs.

[achals]

Everything else looks good, but the only nit I have is that Go feature server is a bit misleading since it's not just Go, and there's no standalone go feature server that can be deployed.

I'd probably called this Go-based feature retrieval and update the docs and flag. What do you think?

[kevjumba]

Fixed.

[kevjumba]

I left it in the feature servers folder since I think out of all folders it's still most relevant to Feature Servers.

[achals]

We should mention that this week be turned on by default at some future version.

[kevjumba]

Done.

[achals]

/lgtm

[achals]

/lgtm

[feast-ci-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: achals, felixwang9817

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [achals,felixwang9817]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment