Dead Links to IO Docs on Paths Page

[favorable-mutation]

At the top of the page for Paths (https://www.scala-sbt.org/1.x/docs/Paths.html), there are links to:

• RichFile (https://www.scala-sbt.org/1.x/api/sbt/io/RichFile.html)
• PathFinder (https://www.scala-sbt.org/1.x/api/sbt/io/PathFinder.html)
• Path (https://www.scala-sbt.org/1.x/api/sbt/io/Path$.html)
• IO (https://www.scala-sbt.org/1.x/api/sbt/io/IO$.html)

All of which are broken.