Add chat template examples

[davidrpugh]

llama-cli supports a number of chat templates that help organize conversations. Need a good usage example for chat templates. Here is the relevant bit from the docs.

--chat-template JINJA_TEMPLATE: This option sets a custom jinja chat template. It accepts a string, not a file name. Default: template taken from model's metadata. Llama.cpp only supports some pre-defined templates. These include the following

• llama2
• llama3
• gemma
• monarch
• chatml
• orion
• vicuna
• vicuna-orca
• deepseek
• command-r
• zephyr

When --in-prefix or --in-suffix options are enabled the chat template ( --chat-template ) is disabled.