docs(readme.md): update readme.md

Author: Metnew

README.md

@@ -1,5 +1,32 @@
 # git-hash-package
 
+### What does it do?
+This package gets info about your git repo (*long hash* + *short hash* + *branch*) and stores this data in your `package.json`.
+
+### Why?
+I faced next issue:  
+If we can't use `git log` inside Docker container in git subrepo in production, we need to store info about git in local files. Storing info about the current git state in `package.json` was a good decision.
+This module solves my issue.
+
 ### Install
+```bash
+npm i git-hash-package
+```
+
+Or if you want to run it globally(I haven't tested it yet):
+
+```
+  npm i -g git-hash-package
+```
 
 ### Usage
+```bash
+git-hash-package # run
+git-hash-package --verbose # run with verbose output about current git state (short + long hashes + branch)
+```
+
+### Author
+Vladimir Metnew <vladimirmetnew@gmail.com>
+
+### License
+MIT

index.js

@@ -6,7 +6,8 @@ const writePkg = require('write-pkg')
 const chalk = require('chalk')
 const options = require('minimist')(process.argv.slice(2))
 
-readPkgUp().then(result => {
+// don't normalize package.json
+readPkgUp({normalize:false}).then(result => {
 	let {pkg} = result
 	const pkgPath = result.path
 	const gitInfo = {
@@ -15,9 +16,6 @@ readPkgUp().then(result => {
 		branch: git.branch()
 	}
 
-	delete pkg.readme
-	delete pkg._id
-
 	const updatedPkg = Object.assign({}, pkg, {
 		git: gitInfo
 	})