DOC: Explain uninitialized weights warning (#2369)
Users sometimes get confused by the warning from transformers that some
weights are uninitialized and need to be trained when they use models
for classification. A recent example is #2367.
Even though the warning does not come from PEFT, let's add a section to
the docs to explain this warning, as the situation is a bit different
here.
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Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
