feat(lec06): adjust title

Author: yanlisa

06-variables-ii/deprecated-eda.qmd …observational-studies/deprecated-eda.qmd06-variables-ii/deprecated-eda.qmd renamed to 06-observational-studies/deprecated-eda.qmd 06-variables-ii/deprecated-eda.qmd renamed to 06-observational-studies/deprecated-eda.qmd

@@ -8,6 +8,14 @@ Quick reference:
 - Optional: `quarto render` builds `_site`.
 - `quarto publish gh-pages` to host `_site` on GitHub pages.
 
+## Python dependencies
+
+```
+datascience
+numpy
+seaborn
+```
+
 ## course-site-quarto
 This repository contains a Quarto-based template for class website. You can see a preview of it at [https://berkeley-cdss.github.io/course-site-quarto](https://berkeley-cdss.github.io/course-site-quarto). This template is intended to be forked and altered for other courses.
 

06-variables-ii/deprecated-index.qmd …servational-studies/deprecated-index.qmd06-variables-ii/deprecated-index.qmd renamed to 06-observational-studies/deprecated-index.qmd 06-variables-ii/deprecated-index.qmd renamed to 06-observational-studies/deprecated-index.qmd

@@ -67,12 +67,12 @@ website:
             text: "Variables and Variable Types"
           - href: 05-variables/units-of-analysis.qmd
             text: "Units of Analysis"
-      - section: "L06: Causality vs. EDA"
-        href: 06-variables-ii/index.qmd
+      - section: "L06: Observational Studies"
+        href: 06-observational-studies/index.qmd
         contents:
-          - href: 06-variables-ii/index.qmd
+          - href: 06-observational-studies/index.qmd
             text: "Causality vs. EDA"
-          - href: 06-variables-ii/sample-population.qmd
+          - href: 06-observational-studies/sample-population.qmd
             text: "Sample vs. Population"
       - href: five-things.qmd
         text: "5 Things to Know"