Adds an .env template (optional for use)

.env

@@ -1,8 +1,12 @@
 # Environmental Variables can be stored here
 # Be sure to uncomment any line you populate
+# Everything is optional, but some features won't work without external API access
 
+# GOOGLE_CLOUD_API_KEY=''
 # SHODAN_API_KEY=''
-
+# REACT_APP_SHODAN_API_KEY=''
 # WHO_API_KEY=''
-
+# REACT_APP_WHO_API_KEY=''
 # SECURITY_TRAILS_API_KEY=''
+# BUILT_WITH_API_KEY=''
+# CI=false