fix: add .env.sample

Author: kastov

.env.sample

@@ -0,0 +1,16 @@
+# Local Development
+
+# Domain of backend, local or production
+DOMAIN_BACKEND=http://127.0.0.1:3003
+
+# Tell frontend to use DOMAIN_BACKEND (1/0)
+DOMAIN_OVERRIDE=1
+
+# 
+NODE_ENV=development
+
+
+### CrowdIn
+CROWDIN=0
+#CROWDIN_API_TOKEN=
+#CROWDIN_PROJECT_ID=