docs: add GitHub discussion badge

[ersachin3112]

This PR contains a:

• [ ] bugfix
• [ ] new feature
• [ ] code refactor
• [ ] test update
• [ ] typo fix
• [x] metadata update

Motivation / Use-Case

add GitHub discussion badge

Breaking Changes

No

Additional Info

No

[codecov[bot]]

Codecov Report

Patch and project coverage have no change.

Comparison is base (5593ee6) 93.33% compared to head (27ed7a6) 93.33%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #514 +/- ## ======================================= Coverage 93.33% 93.33% ======================================= Files 4 4 Lines 150 150 Branches 33 33 ======================================= Hits 140 140 Misses 10 10 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Do you have feedback about the report comment? Let us know in this issue.