FIX: Set correct main script in package.json

 Previously when installed from npm requiring nagios2cfg resulted in the
 obscure error, that it couldn't find any file named
 localhost_nagios2.cfg.

 This was due to package.json pointing to test.js which is now relegated
 to `{ scripts: { test: "node test.js" } }` making it possible to run
 `npm test` to validate functionality.
move poorly/localized(?) named teste.js to test.js
README.md: extend documentation for the package
README.md: fix typo nm install => npm install
Merge pull request #1 from andreas-marschke/fix/package.json

FIX: Set correct main script in package.json
Merge pull request #2 from andreas-marschke/fix/documentation

Fix/documentation
split parse into fromFile() and parse() method
Merge pull request #3 from andreas-marschke/feature/functionality-split

split parse into fromFile() and parse() method