Fix http -> https links that were missed during the transition

[zkamvar]

This does a couple of things:

1. fixes all http -> https links in the non-episode files (majority of which were in demo lessons)
2. adds anchors to headings and replaces the phantom anchors (to fix switch jump links to use identifiers  #1497)
3. fixes warnings about missing files

[github-actions]

Thank you!

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🤖 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}.

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Rendered Changes

🔍 Inspect the changes: https://github.com/carpentries/instructor-training/compare/md-outputs..md-outputs-PR-1519

The following changes were observed in the rendered markdown documents:

 LICENSE.md          |  19 +++---
 checkout.md         |  12 ++--
 demo_lessons.md     | 190 ++++++++++++++++++++++++++--------------------------
 index.md            |   6 +-
 instructor-notes.md |  25 +++----
 md5sum.txt          |  12 ++--
 members.md          |   2 +-
 7 files changed, 131 insertions(+), 135 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.

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⏱️ Updated at 2023-03-31 18:02:37 +0000