updated instructions. Include details for mac + using uniforms

Author: torinmb

README.md

@@ -1,13 +1,23 @@
 # shader-park-touchdesigner
 Render Shader Park sculptures in TouchDesigner
 ### Getting Started 🎉
-Working file available in the dist folder.
-1) Unzip shader-park-core.zip and place the files inside the same folder as ```Shader Park TD.toe```
+Working files are available in the dist folder.
+1) Unzip shader-park-core.zip (Mac users right click on ```shader-park-td-macos``` click Open to give TD access to run the executable).
 2) Open up Shader Park TD.toe and have fun.
+3) Write your Shader Park code in a text DAT and attach it to the Shader_Park_Core component to render (note there are examples and a render network already set up for you to experiment with).
 
-Write your Shader Park code in a txt file and attach it to the Shader_Park_Core component to render.
 
-**Tested on MacOS + Windows with no node.js installed**  
+### Adding Uniforms / Inputs
+If you use any input in your Shader Park code eg:
+```javascript
+let size = input();
+```
+You will need to add a uniform with the same name (in this case ```size```) to the Vectors tab of the pbr2GLSL1 GLSL MAT.
+
+
+---
+
+**This project has been tested on MacOS + Windows with no node.js installed**  
 For Windows this only run on Windows 8.1 and above.
 **Not yet tested on Linux**