docs(readme): general update and refresh (#15784)
docs(readme): general update and refresh (#15784)

add Chrome OS screen reader support
add details about the CDK
remove unused link definitions
jelbourn/material2,angular/components,Jefiozie/material2,jelbourn/material2,josephperrott/material2,andrewseguin/material2,crisbeto/material2,mmalerba/material2,Jefiozie/material2,josephperrott/material2,DevVersion/material2,Jefiozie/material2,josephperrott/material2,jelbourn/material2,andrewseguin/material2,crisbeto/material2,josephperrott/material2,DevVersion/material2,DevVersion/material2,mmalerba/material2,mmalerba/material2,jelbourn/material2,jelbourn/material2,DevVersion/material2,andrewseguin/material2,crisbeto/material2,josephperrott/material2,angular/components,mmalerba/material2,Jefiozie/material2,mmalerba/material2,DevVersion/material2,angular/components,Jefiozie/material2,andrewseguin/material2,angular/components,crisbeto/material2,andrewseguin/material2