Update README.md

Author: vishrutshah

README.md

@@ -1,3 +1,29 @@
+### How to install
+```
+npm install -g [email protected]
+```
+
+### Command Usage
+```
+vishrut@visshamac openapi-diff $ oad compare --help
+Commands:
+  compare <old-spec> <new-spec>  Compares old and new open api specification for
+                                 breaking changes.
+
+Options:
+  --version          Show version number                               [boolean]
+  -l, --logLevel     Set the logging level for console.
+  [choices: "off", "json", "error", "warn", "info", "verbose", "debug", "silly"]
+                                                               [default: "warn"]
+  -f, --logFilepath  Set the log file path. It must be an absolute filepath. By
+                     default the logs will stored in a timestamp based log file
+                     at "/Users/vishrut/oad_output".
+  -j, --inJson       A boolean flag indicating whether output format of the
+                     messages is json.                 [boolean] [default: true]
+  -h, --help         Show help                                         [boolean]
+
+```
+
 ## Build dependencies
 - [Node](https://nodejs.org) (6.9.5 or higher)
 - [Node Package Manager](https://www.npmjs.com/package/npm)
@@ -26,27 +52,6 @@ gulp pack
 npm install -g oad-0.1.0.tgz
 ```
 
-### Command Usage
-```
-vishrut@visshamac openapi-diff $ oad compare --help
-Commands:
-  compare <old-spec> <new-spec>  Compares old and new open api specification for
-                                 breaking changes.
-
-Options:
-  --version          Show version number                               [boolean]
-  -l, --logLevel     Set the logging level for console.
-  [choices: "off", "json", "error", "warn", "info", "verbose", "debug", "silly"]
-                                                               [default: "warn"]
-  -f, --logFilepath  Set the log file path. It must be an absolute filepath. By
-                     default the logs will stored in a timestamp based log file
-                     at "/Users/vishrut/oad_output".
-  -j, --inJson       A boolean flag indicating whether output format of the
-                     messages is json.                 [boolean] [default: true]
-  -h, --help         Show help                                         [boolean]
-
-```
-
 # Contributing
 
 This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [[email protected]](mailto:[email protected]) with any additional questions or comments.