fix: remove internal markup from examples (#545)

Author: MichaelDoyle

examples/autocomplete.prompt

@@ -6,10 +6,10 @@ input:
       userName: string
       isActive: boolean
 ---
-<<<dotprompt:role:system>>>
+{{role "system"}}
 You are a helper.
 
-<<<dotprompt:role:user>>>
+{{role "user"}}
 Hello {{userName}}!
 
 {{! 

examples/features.prompt

@@ -31,27 +31,27 @@ config:
   topK: 40
   topP: 0.95
 ---
-<<<dotprompt:role:system>>>
+{{role "system"}}
 You are a helpful AI assistant. You are an expert in {{context}}.
 Here are some rules:
 {{#each items}}
 - {{this}}
 {{/each}}
 
-<<<dotprompt:role:user>>>
+{{role "user"}}
 Hello, my name is {{name}}.
 Can you analyze this image?
-<<<dotprompt:media:url {{imageUrl}} image/jpeg>>>
+{{media url=imageUrl mime="image/jpeg"}}
 
-<<<dotprompt:role:model>>>
+{{role "model"}}
 I see an image. Let me think about it.
-<<<dotprompt:section thought>>>
+{{section "thought"}}
 The user wants me to analyze the image provided at {{imageUrl}}.
 I should look for key details.
 
-<<<dotprompt:role:user>>>
+{{role "user"}}
 Also, remember our past conversation:
-<<<dotprompt:history>>>
+{{history}}
 
 Please output the result in JSON format.
 {{json this indent=2}}

examples/partials.prompt

@@ -16,10 +16,10 @@ input:
   The `{{> partialName }}` syntax should be distinct from standard tags.
 }}
 
-<<<dotprompt:role:system>>>
+{{role "system"}}
 You are a helpful assistant.
 
-<<<dotprompt:role:user>>>
+{{role "user"}}
 Hello {{userName}}.
 
 Here are your items:

go/example/example.prompt

@@ -13,10 +13,10 @@ input:
 output:
   format: "text"
 ---
-<<<dotprompt:role:user>>>
+{{role "user"}}
 Please summarize the following text.
 
 {{text}}
 
-<<<dotprompt:role:model>>>
+{{role "model"}}
 Yes, I understand. I will summarize it.