A .env file in the working directory is now optional

internal/config/README.md

@@ -8,8 +8,8 @@ environment variables, merged through [Viper](https://github.com/spf13/viper).
 ## Loading order
 `Init(cfgFile, &conf)` builds the configuration in this order:
 
-1. Loads `.env` from the working directory into the environment. A missing
-   `.env` file is an error.
+1. Loads `.env` from the working directory into the environment, if there
+   is one. A `.env` file that can't be read or parsed is an error.
 2. Sets the defaults from the `default` struct tags as Viper defaults.
 3. Reads the config file: `cfgFile` if given, otherwise the first
    `config.yaml` found in `/etc/job-search` then the working directory. If no