web: improve management of `.env` files

- Ignores `.env.production`.
- Improvees `.env.example` file.

Co-Authored-by: iGor milhit <igor@milhit.ch>

web/.env.example

@@ -1,2 +1,5 @@
 # API URL (required)
+# Development
 VITE_API_URL=http://localhost:8000
+# Production 
+VITE_API_URL=https://domaine.org/api

web/.gitignore

@@ -25,12 +25,11 @@ dist-ssr
 
 .vite
 
-.env
+.env*
 .env.local
 .env*.local
 !.env.example
 !.env.template
 !env.development
-!env.production
 
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