Minor documentation revisions from copyediting (#9266)

* typo: Revise "checkout" to "check out"

* typo: Change "seemlessly" to "seamlessly"

* typo: Close parentheses in "Using the tokenizer"

* typo: Add closing parenthesis to supported models aside

* docs: Treat ``position_ids`` as plural

Alternatively, the word "argument" could be added to make the subject singular.

* docs: Remove comma, making subordinate clause

* docs: Remove comma separating verb and direct object

* docs: Fix typo ("next" -> "text")

* docs: Reverse phrase order to simplify sentence

* docs: "quicktour" -> "quick tour"

* docs: "to throw" -> "from throwing"

* docs: Remove disruptive newline in padding/truncation section

* docs: "show exemplary" -> "show examples of"

* docs: "much harder as" -> "much harder than"

* docs: Fix typo "seach" -> "search"

* docs: Fix subject-verb disagreement in WordPiece description

* docs: Fix style in preprocessing.rst

docs/source/training.rst

@@ -14,7 +14,7 @@ Training and fine-tuning
 =======================================================================================================================
 
 Model classes in 🤗 Transformers are designed to be compatible with native PyTorch and TensorFlow 2 and can be used
-seemlessly with either. In this quickstart, we will show how to fine-tune (or train from scratch) a model using the
+seamlessly with either. In this quickstart, we will show how to fine-tune (or train from scratch) a model using the
 standard training tools available in either framework. We will also show how to use our included
 :func:`~transformers.Trainer` class which handles much of the complexity of training for you.