Reference Milestones in README.md (#15)

Update README.md

Add reference to Milestones page

Author: Kitt3120

README.md

@@ -10,6 +10,4 @@ Beta: [![Deploy](https://github.com/Kitt3120/lum/actions/workflows/deploy_prerel
 
 # Collaborating
 
-A board can be viewed [here](https://github.com/users/Kitt3120/projects/3)
-
-Issues can be viewed [here](https://github.com/Kitt3120/lum/issues)
+Checkout out [Milestones](https://github.com/Kitt3120/lum/milestones), [Board](https://github.com/users/Kitt3120/projects/3), and [Issues](https://github.com/Kitt3120/lum/issues)