Implement artifact-level render command with Markdown output and update docs

examples/README.md

@@ -1,8 +1,7 @@
 # Examples
 
 These are small synthetic, copyable example assets for the implemented CLI
-commands.
-This directory is the canonical examples home for documentation.
+commands. This directory is the canonical examples home for documentation.
 
 ## Merge example
 
@@ -55,6 +54,25 @@ go run ./cmd/seriatim trim \
   --keep "1-2"
 ```
 
+## Render example
+
+Input artifact:
+
+- `render/input-intermediate.json`
+
+Expected Markdown output shape:
+
+- `render/output-markdown.md`
+
+Run:
+
+```sh
+go run ./cmd/seriatim render \
+  --input-file examples/render/input-intermediate.json \
+  --output-file /tmp/seriatim-example-render.md \
+  --format markdown
+```
+
 ## YAML rule examples
 
 - `speakers.yml`