Part of excelling at your job is learning new stuff - something that I am absolutely certain you do all the time, even if you only do it during work hours. Maybe this week you are starting a new project and need to learn Vue.
Publish those 100 lines of code to GitHub. Just like that you've demonstrated that:
* You are willing to learn new things.
* You know how to use a little Vue.
* You know how to use a little Git.
Make it clear that it's a learning project - call it "Learning Vue," "Learning C#," "Learning Node" etc. When a hiring manager looks at your profile they will see dozens of technologies that you have at least some experience with.
Edit: if they turn around and demand side projects; you would be completely correct to ask about how many office hours they allocate to side projects. Interviews are a two-way process and the more you stick your neck out, the more you get noticed.