Copyedits and formatting fixes

[kaitlinnewson]

This PR includes a number of formatting fixes and edits I noted during a recent delivery of this material, including:

• Fix some typos throughout
• Improve formatting of some queries, using proper uppercase for keywords and line breaks
• Add a keypoint about comments
• Rename Episode 5 to be consistent with other episodes, using "and"
• Remove reference to Gitter, which is no longer used

[github-actions[bot]]

Thank you!

Thank you for your pull request :smiley:

:robot: This automated message can help you check the rendered files in your submission for clarity. If you have any questions, please feel free to open an issue in {sandpaper}.

If you have files that automatically render output (e.g. R Markdown), then you should check for the following:

• :dart: correct output
• :framed_picture: correct figures
• :question: new warnings
• :bangbang: new errors

Rendered Changes

:mag: Inspect the changes: https://github.com/LibraryCarpentry/lc-sql/compare/md-outputs..md-outputs-PR-169

The following changes were observed in the rendered markdown documents:

 01-introduction.md            | 33 +++++++++++++++++----------------
 02-selecting-sorting-data.md  |  6 +++---
 03-filtering.md               |  2 +-
 04-ordering-commenting.md     |  4 ++--
 05-aggregating-calculating.md |  5 +++--
 08-database-design.md         | 12 +++++-------
 09-create.md                  | 39 ++++++++++++++++++++++++---------------
 discuss.md                    |  1 -
 learner-profiles.md (gone)    |  5 -----
 learner_profile.md            |  2 --
 md5sum.txt                    | 23 +++++++++++------------
 reference.md                  |  6 +-----
 setup.md                      |  4 ++--
 13 files changed, 69 insertions(+), 73 deletions(-)

What does this mean?

If you have source files that require output and figures to be generated (e.g. R Markdown), then it is important to make sure the generated figures and output are reproducible. This output provides a way for you to inspect the output in a diff-friendly manner so that it's easy to see the changes that occur due to new software versions or randomisation.

:stopwatch: Updated at 2024-03-19 12:32:14 +0000

[mimkes]

Thank you, Kaitlin!