Create an index for all the mirrored sites

[nitro2k01]

Add links to all mirrored sites so they are more easy to access the browsable sites. For example, edit README.md such that links to the final sites hosted sites end up in both the repo and in the salvage subdirectory. This would make it slightly easier for an end user to find the mirrors. It would be nice if this could be done automatically, but considering the slow rate of sites added to salvage, doing it manually probably wouldn't be too much work.