change expected port number; add docs about markdown description lists; various cleanup

docs/markdown2html/markdown-format.md

@@ -81,6 +81,60 @@ function say_hello() {
 
 
 
+## Definition / Description Lists {#dl}
+
+Definition lists or description lists (`<dl>` elements) can be rendered using lines that being with a colon (`:`) character.
+
+An unindented line starting with a colon is a `<dt>`, and an indented line starting with a colon is a `<dd>`. Indentation without a starting colon can be used to have multiple lines of content in either type of block. These lists can be nested.
+
+Indentation in `<dl>` blocks must two consecutive spaces; Other indentation styles are not allowed.
+
+```md
+: First Term
+  : First Definition
+  : Second Definition
+
+: Second Term
+  with multiple lines
+  of content
+  : Third Definition
+
+    : Nested List, First Term
+      : Nested List, First Definition
+    : Nested List Second Term
+      : Nested List, First Definition
+        with a _second_ line inside a definition, indicated by indenting again with no colon
+  
+  : Fourth Definition
+
+: Third Term
+  : Fifth Definition
+```
+
+!!! {.markdown-example-output}
+: First Term
+  : First Definition
+  : Second Definition
+
+: Second Term
+  with multiple lines
+  of content
+  : Third Definition
+
+    : Nested List, First Term
+      : Nested List, First Definition
+    : Nested List Second Term
+      : Nested List, First Definition
+        with a _second_ line inside a definition, indicated by indenting again with no colon
+  
+  : Fourth Definition
+
+: Third Term
+  : Fifth Definition
+!!!
+
+
+
 
 ## Feather Icons {#feather}