Update README.md

README.md

 # customspeens-client
  Spin Rhythm XD Custom Songs Client
+ 
+# Compilation Instructions (Windows)
+1. Clone the repository.
+2. Install [node.js](https://nodejs.org/)
+3. Open the node.js command prompt and install electron and electron-dl globally:
+```
+npm install electron -g
+npm install electron-dl -g
+```
+4. Using the node.js command prompt, cd to where you cloned the repository.
+5. Run ```electron .```