Images are broken in README in extension gallery

[bwateratmsft]

Images in the README are not showing up in the extension gallery, both within VSCode and online.

VSCode:

Online:

[bwateratmsft]

@karolz-ms can you take a look at this?

[bwateratmsft]

I looked at old VSIXs, they included the readme files; however the newer ones do not. That is probably what went wrong.

I've just pushed a branch so I'll reassign this to myself.

[bwateratmsft]

Marking with "fixed in next release" and putting in changelog, since it's a pretty user-visible bug.