Add contributing notes

CONTRIBUTING.md

@@ -0,0 +1,56 @@
+# Contributing Notes
+
+There are some things to consider when contributing to this repo:
+
+- make screenshots in high resolution
+  by temporarily increasing the font scaling factor in your OS
+  and using a large display
+- limit the width of images
+- annotate code blocks with `filename="Terminal"` and`filename="Console"`
+  to differentiate Bash and R that should be entered by the user
+  (if there is no file from which the code is an excerpt)
+- Put optional content into a collapsed note
+- Put important content into warning
+- hierarchy of callouts
+  - note
+  - tip
+  - caution
+  - warning
+  - important
+- headings (including tabset tabs and callout titles) are written in title case
+- headings are only H2 and below because the title is already H1
+- callouts use context-specific heading levels that are one below the current heading level
+- R package names are typeset in `monospace`
+- Prefer R packages that follow the [tinyverse](https://www.tinyverse.org/) philosophy,
+  that is, have a lightweight dependency footprint.
+  All packages need to be downloaded by `renv` and (worst case) compiled during the tutorial,
+  which better not take too long.
+  Use `pak::pkg_deps()` to count the total number of package dependencies.
+- Write license abbreviations with no-break spaces
+  (e.g., write `CC\ BY\ 4.0` rather than `CC BY 4.0`)
+- When writing markdown:
+  - use [semantic linefeeds][semantic-linefeeds] to ease change tracking,
+    except for exact quotes (as they won't be updated)
+    and for example code in code blocks
+    (to allow for wrapping on the website as required by the user's device)
+  - use [regular footnotes][regular-footnotes] rather than [inline footnotes][inline-footnotes]
+    to increase the readability of markdown
+    (except for short notes or at the end of lines)
+  - use [reference links][reference-links] rather than [inline links][inline-links]
+    to increase the readability of markdown
+    (except for short links or at the end of a line)
+- If the (R package/system) dependencies that are required to work through the tutorial change,
+  make sure to adjust the respective section in `make_readme.qmd` accordingly.
+- When making significant contributions,
+  add people to the `CITATION.cff` file and mention them in `about.qmd`.
+- keep usage of terms consistent, for example:
+  - always write _data dictionary_ or always write _codebook_ (but don't mix)
+    - in the case of this tutorial, the convention is to write _data dictionary_
+  - always write _data set_ or always write _dataset_ (but don't mix)
+    - in the case of this tutorial, the convention is to write _data set_
+
+[semantic-linefeeds]: https://rhodesmill.org/brandon/2012/one-sentence-per-line/
+[regular-footnotes]: https://pandoc.org/MANUAL.html#extension-footnotes
+[inline-footnotes]: https://pandoc.org/MANUAL.html#extension-inline_notes
+[reference-links]: https://pandoc.org/MANUAL.html#reference-links
+[inline-links]: https://pandoc.org/MANUAL.html#inline-links