Allow setting config.js alternative on boot

Closes #105

README.md

@@ -31,7 +31,7 @@ STDOUT.  Check the README there for more details and usages.
 1.  Download the package, and expand it
 2.  Explore the settings inside of config.js, but the defaults should be good
 3.  `npm install`
-4.  `npm start`
+4.  `npm start` (you may specify an optional `<config-path>` as well)
 
 ## Settings
 
@@ -52,7 +52,7 @@ STDOUT.  Check the README there for more details and usages.
 
 When present, the `rateLimits` option enables built-in rate limiting courtesy
 of `connect-ratelimit`.  Any of the options supported by that library can be
-used and set in `config.json`.
+used and set in `config.js`.
 
 See the README for [connect-ratelimit](https://github.com/dharmafly/connect-ratelimit)
 for more information!

server.js

@@ -11,7 +11,8 @@ var connect_rate_limit = require('connect-ratelimit');
 var DocumentHandler = require('./lib/document_handler');
 
 // Load the configuration and set some defaults
-var config = JSON.parse(fs.readFileSync('./config.js', 'utf8'));
+const configPath = process.argv.length <= 2 ? 'config.js' : process.argv[2];
+const config = JSON.parse(fs.readFileSync(configPath, 'utf8'));
 config.port = process.env.PORT || config.port || 7777;
 config.host = process.env.HOST || config.host || 'localhost';