Add figma link in issue template

Signed-off-by: Sahil Yeole <[email protected]>

Author: beelchester

.github/ISSUE_TEMPLATE/documentation.md

@@ -14,3 +14,4 @@ assignees: ''
 - [Meshery documentation site](https://docs.meshery.io/)
 - [Meshery documentation source](https://github.com/layer5io/meshery/tree/master/docs)
 - [Instructions for contributing to documentation](https://github.com/layer5io/meshery/blob/master/CONTRIBUTING.md#documentation-contribution-flow)
+- 🎨 Wireframes and [designs for Meshery UI](https://www.figma.com/file/SMP3zxOjZztdOLtgN4dS2W/Meshery-UI) in Figma [(open invite)](https://www.figma.com/team_invite/redeem/qJy1c95qirjgWQODApilR9)