let's add the docs anyway

2023/2023-03-09_ProgrammingWithJulia-2/slides/2a-details.md

@@ -35,3 +35,24 @@ using Test, MyPackageName
   @test f() == 123
 end
 ```
+
+
+
+# How do I document my code?
+
+Docstrings are automatically sourced and exposed to the help system (and `?`)
+
+```julia
+"""
+    f()
+
+This returns a pretty good randomly chosen constant.
+"""
+f() = 123
+```
+
+Extra packages:
+- `Documenter.jl` makes a nice website out of the documentation
+  - (and uploads it to e.g. github pages)
+- `DocStringExtensions.jl` provide some macros to simplify writing docstrings
+  - (e.g., typesetting of the full function type signature)