Add env documentation in the --help message

Author: suricactus

README.md

@@ -67,8 +67,8 @@ qfieldcloud-cli --json list-projects
 Environment variables can be used instead of passing some common global options.
 
 - `QFIELDCLOUD_API` - QFieldCloud API endpoint URL
-- `QFIELDCLOUD_USERNAME` - QFieldCloud username or email. Need `QFIELDCLOUD_PASSWORD` to be set.
-- `QFIELDCLOUD_PASSWORD` - Password. Needs `QFIELDCLOUD_USERNAME` to be set.
+- `QFIELDCLOUD_USERNAME` - QFieldCloud username or email. Requires `QFIELDCLOUD_PASSWORD` to be set.
+- `QFIELDCLOUD_PASSWORD` - Password. Requires `QFIELDCLOUD_USERNAME` to be set.
 - `QFIELDCLOUD_TOKEN` - Token that can be used instead of passing username and password. It can be obtained by running `qfieldcloud-cli login`.
 - `QFIELDCLOUD_VERIFY_SSL` - When set to `0` has the same effect as passing `--no-verify-ssl`.