Adding code guidelines

[martin-gaievski]

Description

There are no code guidelines for the repo, this slows down new contributors and add cycles during code reviews.

Check List

• All tests pass
• Commits are signed as per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.69%. Comparing base (628cb64) to head (609bfe5).
Report is 1 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #502      +/-   ##
============================================
- Coverage     81.74%   81.69%   -0.06%     
+ Complexity     2511     2510       -1     
============================================
  Files           190      190              
  Lines          8564     8564              
  Branches       1436     1436              
============================================
- Hits           7001     6996       -5     
- Misses         1006     1014       +8     
+ Partials        557      554       -3     

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[jmazanec15]

@martin-gaievski Can we update table of contents on dev guide as well?

[yuye-aws]

Hi @martin-gaievski ! Are you still taking care of this PR? Why this is still draft?

[martin-gaievski]

@yuye-aws resumed work on this PR, feel free to leave comments

[vibrantvarun]

@martin-gaievski Can we resurrect this PR ?

[martin-gaievski]

@martin-gaievski Can we resurrect this PR ?

yup, we can for sure, rebased it on latest main

[martin-gaievski]

BWC are failing, looks like ml-commons related problem:

https://github.com/opensearch-project/neural-search/actions/runs/12998883054/job/36253263991?pr=502#step:4:409

    org.opensearch.client.ResponseException: method [POST], host [http://[::1]:39469], URI [/neuralsearch-bwc-testsparseencodingprocessor_e2eflow/_doc/1?refresh=true], status line [HTTP/1.1 500 Internal Server Error]
    {"error":{"root_cause":[{"type":"null_pointer_exception","reason":"Cannot invoke \"org.opensearch.ml.common.output.model.ModelTensorOutput.getMlModelOutputs()\" because \"modelTensorOutput\" is null"}],"type":"null_pointer_exception","reason":"Cannot invoke \"org.opensearch.ml.common.output.model.ModelTensorOutput.getMlModelOutputs()\" because \"modelTensorOutput\" is null"},"status":500}

[vibrantvarun]

lgtm, thanks