v1.1 release notes (#257)

* Initial commit of v1.1 release notes

* Add notable changess for v1.1 release notes

* Add Helm Charts Support in highlights of v1.1 release notes

* Add TGI-Gaudi 2.0.6 commit to the notable changes of v1.1 release notes.

* Add contributors section in v1.1 release notes

* Apply Malini's suggestions from code review

Co-authored-by: Malini Bhandaru <[email protected]>
Co-authored-by: Eero Tamminen <[email protected]>

* Update release_notes/v1.1.md according to Eero's suggestions

Co-authored-by: Eero Tamminen <[email protected]>

* Update v1.1 release notes according to review suggestions.

* Re-format "What's New" section of v1.1 release

* Apply suggestions from Eero's review

Co-authored-by: Eero Tamminen <[email protected]>

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Co-authored-by: Malini Bhandaru <[email protected]>
Co-authored-by: Eero Tamminen <[email protected]>
Co-authored-by: Tian, Feng <[email protected]>