feat: added perplexity model

.env.example

@@ -70,6 +70,11 @@ LMSTUDIO_API_BASE_URL=
 # You only need this environment variable set if you want to use xAI models
 XAI_API_KEY=
 
+# Get your Perplexity API Key here - 
+# https://www.perplexity.ai/settings/api
+# You only need this environment variable set if you want to use Perplexity models
+PERPLEXITY_API_KEY=
+
 # Include this environment variable if you want more logging for debugging locally
 VITE_LOG_LEVEL=debug