New RCE alt-text option before image is inserted

[m_fowler]

New RCE should provide alt-text input option before image insertion. This will help promote good practice and accessibility when creating content. 

This idea has been developed and deployed to Canvas

For more information, please read through the https://community.canvaslms.com/docs/DOC-26928-canvas-deploy-notes-2020-08-12 

[Stef_retired]

Comments from Instructure

When an image is uploaded into the New Rich Content Editor, the Upload Image window includes options to add alternative text, identify an image as decorative, and select a display option. For more information, please read through the Canvas Deploy Notes (2020-08-12).