Adding gpt-3.5-turbo-16k Modal (#215)

Author: sam2332

src/commands/config.ts

@@ -120,7 +120,7 @@ export const configValidators = {
   [CONFIG_KEYS.OCO_MODEL](value: any) {
     validateConfig(
       CONFIG_KEYS.OCO_MODEL,
-      ['gpt-3.5-turbo', 'gpt-4'].includes(value),
+      ['gpt-3.5-turbo', 'gpt-4','gpt-3.5-turbo-16k'].includes(value),
       `${value} is not supported yet, use 'gpt-4' or 'gpt-3.5-turbo' (default)`
     );
     return value;