chore:improve .env.example documentation

- Improve .env.example documentation
  - Convert inline comments to multi-line format for better readability
  - Add more descriptive explanations for each configuration option
  - Maintain professional tone while preserving important guidance
  - Better explain use cases (e.g., air-gapped environments)

.env.example

@@ -1,9 +1,20 @@
-PUB_HOSTNAME=localhost:5173 # only gets used for plausible (for now)
-PUB_PLAUSIBLE_URL=https://plausible.example.com # can be empty
-PUB_ENV=development # "production", "development", or "nightly"
-PUB_VERTD_URL=https://vertd.vert.sh # default vertd instance
-PUB_DISABLE_ALL_EXTERNAL_REQUESTS=false # disables vertd, stripe, plausible, etc. use if your boss complains about privacy
+# The hostname used for analytics tracking (currently only used by Plausible)
+PUB_HOSTNAME=localhost:5173
 
-# please do not change these. donations help a lot
+# URL for your Plausible Analytics instance (leave empty to disable analytics)
+PUB_PLAUSIBLE_URL=https://plausible.example.com
+
+# Application environment: "production", "development", or "nightly"
+PUB_ENV=development
+
+# URL of the vertd daemon for video conversion (default: official VERT instance)
+PUB_VERTD_URL=https://vertd.vert.sh
+
+# Set to true to disable all external requests (vertd, Stripe, Plausible, etc.)
+# Useful for privacy-focused deployments or air-gapped environments
+PUB_DISABLE_ALL_EXTERNAL_REQUESTS=false
+
+# Donation settings - These support the project's development
+# Please keep these values to help maintain and improve VERT
 PUB_DONATION_URL=https://donations.vert.sh
 PUB_STRIPE_KEY=pk_live_51RDVmAGSxPVad6bQwzVNnbc28nlmzA30krLWk1fefCMpUPiSRPkavMMbGqa8A3lUaOCMlsUEVy2CWDYg0ip3aPpL00ZJlsMkf2