Updated the link to the guide

Still a fantastic guide

README.md

@@ -2,7 +2,7 @@
 [<center><img src="https://lh3.googleusercontent.com/-p9S_rIap_No/V9iIHcrU1_I/AAAAAAAAEPk/Mba0HIFDvR8oE_1hmfj0SGWqlx561mZBwCL0B/w971-h547-n-no/12.png" height="100%" width="100%;"/></center>](https://github.com/dirtyunicorns)
 
 ## Setting up your build environment and syncing our source ##
-To set up your build environment and sync DU, please follow this guide: [Link](https://raw.githubusercontent.com/nathanchance/Android-Tools/master/Guides/Building_AOSP.txt)
+To set up your build environment and sync DU, please follow this guide: [Link](https://raw.githubusercontent.com/nathanchance/android-tools/main/guides/building_aosp.txt)
 
 ## Submitting Patches ##
 Dirty Unicorns is an open source project and welcomes new contributors.