Add framework documentation and offline example

examples/go-library/prepare/prompt.yaml

@@ -0,0 +1,16 @@
+id: example.prepare
+version: "1.0.0"
+default_profile: offline-example
+description: Prepare a prompt without contacting a model provider.
+inputs:
+  - name: note
+    required: true
+    content_type: text/plain
+messages:
+  - role: system
+    content: Summarize the note in one sentence.
+  - role: user
+    content: '{{input "note"}}'
+output:
+  format: text
+  validation_mode: basic