Config: Default None -> Empty in comments

Empty makes more sense when talking about empty fields.

Signed-off-by: kingbri <bdashore3@proton.me>

config_sample.yml

@@ -42,11 +42,11 @@ model:
 
   # The below parameters apply only if model_name is set
 
-  # Max sequence length (default: None)
+  # Max sequence length (default: Empty)
   # Fetched from the model's base sequence length in config.json by default
   max_seq_len:
 
-  # Overrides base model context length (default: None)
+  # Overrides base model context length (default: Empty)
   # WARNING: Don't set this unless you know what you're doing!
   # Only use this if the model's base sequence length in config.json is incorrect (ex. Mistral/Mixtral models)
   override_base_seq_len:
@@ -73,11 +73,11 @@ model:
   # Enable 8 bit cache mode for VRAM savings (slight performance hit). Possible values FP16, FP8. (default: FP16)
   cache_mode: FP16
 
-  # Set the prompt template for this model. If empty, chat completions will be disabled. (default: None)
+  # Set the prompt template for this model. If empty, chat completions will be disabled. (default: Empty)
   # NOTE: Only works with chat completion message lists!
   prompt_template:
 
-  # Number of experts to use PER TOKEN. Fetched from the model's config.json if not specified (default: None)
+  # Number of experts to use PER TOKEN. Fetched from the model's config.json if not specified (default: Empty)
   # WARNING: Don't set this unless you know what you're doing!
   # NOTE: For MoE models (ex. Mixtral) only!
   num_experts_per_token: