Update: add types and why section

Author: JPeer264

README.md

@@ -2,6 +2,12 @@
 
 [![Build Status](https://travis-ci.org/JPeer264/node-semantic-git-commit-cli.svg?branch=master)](https://travis-ci.org/JPeer264/node-semantic-git-commit-cli) [![Coverage Status](https://coveralls.io/repos/github/JPeer264/node-semantic-git-commit-cli/badge.svg?branch=master)](https://coveralls.io/github/JPeer264/node-semantic-git-commit-cli?branch=master)
 
+> A CLI to keep semantic git commits. With emoji support 😄 👍
+
+## Why?
+
+Many projects got different git commit rules. It is hard to remember them all.
+
 ## Usage
 
 ```sh
@@ -20,3 +26,49 @@ or even shorter:
 ```sh
 $ sgc
 ```
+
+## Config
+
+> Just create a `.sgcrc` in your project root or you can add everything in your `package.json` with the value `sgc`
+
+### Types
+
+> Types will define your git commits.
+
+**Keys**
+
+- `prefix` - This will be your commit convention and will be your start of your commit - e.g.: `Feat:`
+- `description` (optional) - The description to explain what your prefix is about
+- `emoji` (optional) - An emoji which will be appended at the beginning of the commit ([Emoji Cheat Sheet](https://www.webpagefx.com/tools/emoji-cheat-sheet/))
+
+The `.sgcrc`:
+
+```json
+{
+    "types": [
+      {
+        "emoji": ":sparkles:",
+        "prefix": "Feat:",
+        "description": "Any description to describe the prefix"
+      }
+    ]
+}
+```
+
+The `package.json`:
+
+```json
+{
+    "name": "Your application name",
+    "version": "1.0.0",
+    "sgc": {
+        "types": [
+            {
+              "emoji": ":sparkles:",
+              "prefix": "Feat:",
+              "description": "Any description to describe the prefix"
+            }
+        ]
+    }
+}
+```