Added info on widget as tooltip + widget builders for custom widget

[pinkeshmars]

Description

Added info on widget as tooltip and widget builders for custom widget

Linear ticket and magic word Fixes DEVR-646

Type of change

• [ ] Typo fix
• [x] New feature
• [ ] Enhancement to current docs
• [ ] Removed outdated references
• [ ] Update assets

[stackblitz[bot]]

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