package.json: tell npx the nearly package name

[msimerson]

fixes #33

I hope. If not, I'll try the npx --no-install option next.

[msimerson]

➜  node-address-rfc2821 git:(master) npm publish
npm notice 
npm notice 📦  address-rfc2821@1.2.1
npm notice === Tarball Contents === 
npm notice 4.7kB test/address.js
npm notice 2.4kB index.js       
npm notice 1.2kB package.json   
npm notice 836B  Changes.md     
npm notice 3.1kB README.md      
npm notice 4.4kB grammar.ne     
npm notice === Tarball Details === 
npm notice name:          address-rfc2821                         
npm notice version:       1.2.1                                   
npm notice package size:  5.5 kB                                  
npm notice unpacked size: 16.5 kB                                 
npm notice shasum:        92db9ee31867e685d3815e70d6170b63a753f007
npm notice integrity:     sha512-6cycRSgp+xdQQ[...]9dV8XJuSOkZ+w==
npm notice total files:   6                                       
npm notice 
+ address-rfc2821@1.2.1