added sample code to user_guide.md

[harrowmykel]

Description

This change adds a sample code to readme so that developers can easily get started

Issues Resolved

Closes #27 #46

[shyim]

Can you sign also the CLA?

[harrowmykel]

Yes I signed it

[shyim]

GitHub Action is still red

[harrowmykel]

Yeah because of this

https://github.com/opensearch-project/opensearch-php/pull/107/checks?check_run_id=9768100210

[dblock]

This PR has a lot more than a sample :) Rebase?

[mo-aro-etailer]

I only added a sample. All other changes are because i used a master branch of the project that has been updated.

Kindly consider making it easier to contribute to this open-sourced project. Why do we have to provide our personal email to a public repository before we can contribute? We should be able to sign with our username instead.

[codecov-commenter]

Codecov Report

Merging #107 (bb75371) into main (849734d) will not change coverage.
The diff coverage is n/a.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

@@            Coverage Diff            @@
##               main     #107   +/-   ##
=========================================
  Coverage     23.91%   23.91%           
  Complexity     1935     1935           
=========================================
  Files           245      245           
  Lines          6848     6848           
=========================================
  Hits           1638     1638           
  Misses         5210     5210           

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.