Update evaluation.mdx

[practice-dump]

According to the definition given of Insertion and deletion operation, changed content a bit

Substitutions (S): where we transcribe the wrong word in our prediction (“sit” instead of “sat”)
Insertions (I): where we add an extra word in our prediction
Deletions (D): where we remove a word in our prediction
(Taken from course page)

So here it is mentioned we perform operation on prediction. So if "mat" is not predicted by the model, it should be inserted not deleted right?

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[MKhalusova]

The original description is correct. The substitutions, insertions, and deletions are types of errors that we observe (e.g. there's no "mat", it's missing, aka "deleted"), not actions that need to be taken to fix errors.