Update marble images for old operators

[moniuch]

tap, catchError and throwError operators jsdoc still refer to the old marble images.

• https://rxjs-dev.firebaseapp.com/api/index/tap shows https://rxjs-dev.firebaseapp.com/img/do.png
• https://rxjs-dev.firebaseapp.com/api/index/catchError shows https://rxjs-dev.firebaseapp.com/img/catch.png
• https://rxjs-dev.firebaseapp.com/api/index/throwError shows https://rxjs-dev.firebaseapp.com/img/throw.png

Not sure about how these images are generated. In case it is a manual process, then new images have to be created and made available with new file names.

Still fresh to this project, so might be missing a piece of info but - it would be good to have this marble generation process documented to better handle changes in the future.