Preprocess on custom dataset

[Sushant581]

How can we use preprocessing on our dataset? The Readme does not explain preprocessing step or how to create/Understand following statement in README

"src_dir should contain the following files (using test split as an example):
test.source
test.source.tokenized
test.target
test.target.tokenized
test.out
test.out.tokenized"

so that we can run SimCLS on our dataset