Add SECURITY.md file

[sfc-gh-pfus]

Description

SNOW-626566 Added security.md

Checklist

• [x] Created tests which fail without the change (if possible)
• [x] Extended the README / documentation, if necessary

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 77.07%. Comparing base (04153f3) to head (4941a9e). Report is 1 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1099 +/- ## ========================================== + Coverage 77.05% 77.07% +0.01% ========================================== Files 52 52 Lines 10949 10947 -2 ========================================== Hits 8437 8437 + Misses 2512 2510 -2 ```

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