Update README.md

Author: MerrickZ

README.md

@@ -1,7 +1,7 @@
 rmdup
 ========
 
-Remove Duplicated Files in a really fast way.
+Remove Duplicated Files in a *really fast* way.
 
 ## How to use
 
@@ -17,4 +17,10 @@ e.g.
 
 ## Requirements
 
-.net 8
+[.net 8 SDK](https://dotnet.microsoft.com/en-us/download) to build.
+
+## How to build
+
+1. clone this repo
+2. make sure you have .net 8 SDK installed
+3. run `dotnet build` in this project's directory