Wording and clarity edits

[cassws]

Phrasing changes to increase clarity in some parts of lesson, such as:

• Rewording "methods" as "processes" so learners don't confuse with object methods
• Ambiguity re: CSV's and separators
• Acknowledge dimension block at end of console output for dataframe (without .head() or print(df)
• misc. phrasing

Note that the clarity around methods would be compatible with the edits in #452 (which I think are great!)

Thank you for considering!

[maxim-belkin]

Thank you for your contribution, @zoews! I have a few comments/requests but this is an excellent PR! 👍

[tobyhodges]

I'm helping the current lesson Maintainers process outstanding pull requests on this repository, in preparation for transition to the new lesson infrastructure.

Thank you for contributing these changes, @zoews. I agree with @maxim-belkin's suggestions for how the changes could be improved further. If you would like to return and update this pull request to address his comments before the end of this month, I would be delighted to merge your enhancements.

When the infrastructure transition takes place in May 2023, this pull request will become invalid and will have to be closed.

[LilithElina]

I converted the changes @maxim-belkin proposed into code change suggestions, so @zoews or @tobyhodges can easily commit them if they accept them to merge this PR before May. Only for the last change (to move a sentence to below a code box) I had to create a new commit. I hope that's alright with everyone involved.

[maxim-belkin]

Thanks you, @LilithElina! Glad this lesson is in good hands now.
Thank you, @tobyhodges, too! Happy to see that The Carpentries' infrastructure is evolving.