fix: Adding README infos about the JWT token generation

README.md

@@ -71,6 +71,18 @@ Open `.env` and set every value — see [Environment variables](#environment-var
   ```bash
   node -e "console.log(require('crypto').randomBytes(48).toString('hex'))"
   ```
+
+  You may use alternatives for Linux-based distros, like this OpenSSL one:
+  ```bash
+  openssl rand -hex 48
+  ```
+
+  Or even lower-level tools from Linux/UNIX entropy pool:
+  ```bash
+  head -c 48 /dev/urandom | xxd -p -c 48
+  # or
+  head -c 48 /dev/urandom | hexdump -e '48/1 "%02x"'
+  ```
 - `POSTGRES_PASSWORD`
 - `POSTGRES_USERS_PASSWORD`
 - `ADMIN_PASSWORD`