fix: rm README with dead AWS S3 links (#819)

### Briefly, what does this PR introduce?
These are not maintained or standard links. The files are gone. The
provided ddsim commands are diluting the central documentation efforts.

### What kind of change does this PR introduce?
- [x] Bug fix (issue: dead links)
- [ ] New feature (issue #__)
- [ ] Documentation update
- [ ] Other: __

### Please check if this PR fulfills the following:
- [ ] Tests for the changes have been added
- [ ] Documentation has been added / updated
- [ ] Changes have been communicated to collaborators

### Does this PR introduce breaking changes? What changes might users
need to make to their code?
No.

### Does this PR change default behavior?
No.

Co-authored-by: Dmitry Kalinkin <[email protected]>