Added .env welcome_message info

Added information on the WELCOME_MESSAGE .env variable.

README.md

@@ -67,6 +67,8 @@ You also need to add the allowed guilds that the bot can operate on, this is the
 
 You also need to add the roles that can use the bot, this is the `ALLOWED_ROLES` field, enter role names here, separated by commas. Currently, there is no way to give everybody access to the bot, and you have to use roles, but it will be done soon.
 
+You can optionally add a fallback welcomming message for the bot to use when new members join. If enabled, the bot will DM new members with a welcomming message generated by GPT3. If the call to GPT3 fails, the string used in the .env file is used. As further redundency, a hardcoded welcomming message is used.  
+
 ```
 OPENAI_TOKEN="<openai_api_token>"
 DISCORD_TOKEN="<discord_bot_token>"
@@ -74,6 +76,7 @@ DEBUG_GUILD="974519864045756446"   #discord_server_id
 DEBUG_CHANNEL="977697652147892304"  #discord_chanel_id
 ALLOWED_GUILDS="971268468148166697,971268468148166697"
 ALLOWED_ROLES="Admin,gpt"
+WELCOME_MESSAGE="Hi There! Welcome to our Discord server. We hope you'll enjoy our server and we look forward to engaging with you!" #Optional
 ```
 
 Optionally, you can include your own conversation starter text for the bot that's used with `!g converse`, with `CONVERSATION_STARTER_TEXT`