feat: update regular_mistral.jinja with v3.0 soft-spectrum and regular mode

templates/regular_mistral.jinja

@@ -0,0 +1,10 @@
+{{- bos_token -}}
+{%- for message in messages -%}
+    {%- if message['role'] == 'user' -%}
+        {{- '[INST] ' + message['content'] | trim + ' [/INST]' -}}
+    {%- elif message['role'] == 'assistant' -%}
+        {{- ' ' + message['content'] | trim + eos_token -}}
+    {%- elif message['role'] == 'system' -%}
+        {{- '[INST] ' + message['content'] | trim + ' [/INST]' -}}
+    {%- endif -%}
+{%- endfor -%}