add link to finding things in shell lesson

[maneesha]

As this lesson references grep and finding things from the shell lesson, this PR adds a link directly to that lesson.

[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/swcarpentry/r-novice-gapminder/compare/md-outputs..md-outputs-PR-851

The following changes were observed in the rendered markdown documents:

 07-control-flow.md | 3 ++-
 md5sum.txt         | 2 +-
 2 files changed, 3 insertions(+), 2 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 2023-07-05 19:47:55 +0000

[matthieu-bruneaux]

Thank you @maneesha!