Add basic mermaid diagram docs, update lockfile

Author: froggleston

episodes/episodes.Rmd

@@ -990,6 +990,8 @@ The reasons the others were incorrect is:
 
 ## Figures
 
+### Standard Markdown Figures
+
 To include figures, place them in the `episodes/fig` folder and reference them
 directly like so using standard markdown format, with one twist: add an `alt`
 attribute at the end to make it accessible like this:
@@ -1072,6 +1074,54 @@ pie(
 )
 ```
 
+### Mermaid Diagrams
+
+[Mermaid diagrams](https://mermaid-js.github.io/mermaid/#/) can be included in lessons by using the `mermaid` fenced div and a code fragment the mermaid syntax.
+
+The following example creates a simple flowchart:
+```
+    flowchart LR
+        accTitle: {A short figure title}
+        accDescr: {A longer description of the figure, highlighting important elements}
+        A(1. Step A)
+        A --> B(2. Step B)
+        C("`3. Step C
+        - A thing
+        - Another thing
+        - Something else`")
+        B --> C
+        C --> D(4. Step D)
+```
+
+The resulting mermaid diagram will be rendered as:
+
+```mermaid
+    flowchart LR
+        accTitle: {A short figure title}
+        accDescr: {A longer description of the figure, highlighting important elements}
+        A(1. Step A)
+        A --> B(2. Step B)
+        C("`3. Step C
+        - A thing
+        - Another thing
+        - Something else`")
+        B --> C
+        C --> D(4. Step D)
+```
+
+::::::::::::::::::::: callout
+
+### Accessibility of Mermaid Diagrams
+
+Note that both the `accTitle` and `accDescr` fields in the mermaid code block need to be supplied to produce an accessible figure caption!
+
+`accTitle` provides a short title for the figure, and `accDescr` provides a longer form description of the figure that highlights important elements.
+
+Both of these fields are read by screen readers to provide an accessible description of the figure.
+
+:::::::::::::::::::::::::::::
+
+
 ## Math
 
 One of our episodes contains $\LaTeX$ equations when describing how to create dynamic reports with {knitr}, so we now use mathjax to describe this:

renv/profiles/lesson-requirements/renv.lock

@@ -1,6 +1,6 @@
 {
   "R": {
-    "Version": "4.5.3",
+    "Version": "4.5.2",
     "Repositories": [
       {
         "Name": "carpentries",
@@ -725,7 +725,7 @@
       "Config/testthat/start-first": "bioconductor,python,install,restore,snapshot,retrieve,remotes",
       "Author": "Kevin Ushey [aut, cre] (ORCID: <https://orcid.org/0000-0003-2880-7407>), Hadley Wickham [aut] (ORCID: <https://orcid.org/0000-0003-4757-117X>), Posit Software, PBC [cph, fnd]",
       "Maintainer": "Kevin Ushey <kevin@rstudio.com>",
-      "Repository": "https://packagemanager.posit.co/cran/__linux__/jammy/latest"
+      "Repository": "RSPM"
     },
     "rlang": {
       "Package": "rlang",