Good on Github. Not all companies will even make small concessions in this realm so I applaud them. I'm hesitant to write this but there are some false comments specifically about my employer in this thread so I will.
I work for Microsoft and our policies are draconian. They of course make the standard claims of anything created on their hardware, using their software, or transmitted on their network. But to be exempt from their IP claim it also cannot be related to Microsoft business, or "anticipated business, research or development of Microsoft." Which of course is everything in the software world. It makes it particularly difficult since we're supposed to evangelize their stack and toolchain. But because of these policies I pay out of pocket for my own hardware, dev tools, as well as exclusively use GCP/AWS.
They do have a program they're very proud of where they let you use software you're given as an employee if you're developing an app for the windows store, but it's so vague as to be legally useless.