Revise README for real-time updates and GCP access

Updated README with real-time information and access instructions.

Author: JBlaschke

README.md

@@ -2,4 +2,8 @@
 
 # The Julia Language for Productive High-Performance Computing Tutorial @ SC25
 
-Information will appear here soon, please check in later
+This information will be updated in real time, please check here (and `git pull`) frequently!
+
+Access instructions for the GCP instance: https://go.lbl.gov
+
+If you are interested in more examples and more materials, please check out the [SC 24 Tutorial](https://github.com/JuliaParallel/julia-hpc-tutorial-sc24)