It was only required for the MemoryFileSystem,
not the real FileSystem, so writing an array would concatenate all
the lines together without any spaces or newlines.

Specifically, we don't want to *join* the lines, but rather append to each line.
This lets us avoid having to manually add a newline to the end, and handle them all at once.

Also, we chomp every line on read (and before write) so we don't duplicate any newlines

This is so when they're read out, they do not contain line breaks at the end of each line's string. Later on, when this content is passed to write, it is joined with , which will add newlines

This separates the concerns, so the adapters only write **String**s,
they don't do any joining or coercion.