Website: Update lead source on contact records (#20383)

Changes:
- Updated signup.js to add the "Website - Sign up" lead source to new
contact records.

website/api/controllers/entrance/signup.js

@@ -144,6 +144,7 @@ the account verification message.)`,
       firstName: firstName,
       lastName: lastName,
       organization: organization,
+      leadSource: 'Website - Sign up'
     }).exec((err)=>{
       if(err){
         sails.log.warn(`Background task failed: When a user (email: ${newEmailAddress} signed up for a fleetdm.com account, a Contact and Account record could not be created/updated in the CRM.`, err);