mashcard History snapshot should be read-only

Describe the bug

When viewing a history snapshot, we can still edit its content (though they are not saved).

https://user-images.githubusercontent.com/5107241/177431503-54d9207c-029a-484d-a21b-de6d9b5ba35d.mov

To Reproduce

The editor should be in readonly mode when viewing a history snapshot.

Expected behavior

No response

Additional context

No response

Logs/tracebacks

No response

Jul 05 '22 23:07 stackia

@crete555 Do we have designs for the read-only history page?

Jul 06 '22 05:07 stackia

@Brickdoctor @ziyanchen327 @zaotang

Jul 18 '22 06:07 stackia

This issue has been automatically marked as stale because it has been open for 30 days with no response from the author. It will be closed in next 7 days if no further activity occurs from the issue author.

Aug 30 '22 00:08 github-actions[bot]

This issue has been closed because it has not received response from the issue author.

Sep 07 '22 00:09 github-actions[bot]