update installation instrcutions

README.md

@@ -13,4 +13,26 @@
     ✔ git 2.14.1
     ✔ gradle 4.0.1
 
+## Installing
+
+Just download the `has` script in your path. 
+
+If you are lazy, you can has of the internet as well
+
+    curl -sL https://raw.githubusercontent.com/kdabir/has/master/has | bash -s git node npm
+    ✔ git 2.14.1
+    ✔ node 8.2.1
+    ✔ npm 5.3.0
+
+
+And if that's too much of typing everytime, setup an alias
+    
+    alias has="curl -sL https://raw.githubusercontent.com/kdabir/has/master/has | bash -s"
+
+And uses it
+
+    $ has git
+    ✔ git 2.14.1
+
+
 ### ♥