I'm on mobile just now, so I can't give you the link or even the name right now, but there is a good spell checker extension available. I use it on Windows, but

I'm on mobile just now, so I can't give you the link or even the name right now, but there is a good spell checker extension available. I use it on Windows, but presume it works elsewhere too. IIRC, it was a little fiddly to setup (think I had to download spell check files separately), but it's been plain sailing after that. I mainly use JetBrains Rider though, and that has really good spell checking support built-in. Something I really like about Rider's support is that, just like lining rules, you have the option of saving additional words at the "Team Shared" level, so the whole team can use the same extra dictionary words. The same function works in Visual Studio with ReSharper installed, and presumably it's available in all JetBrains IntelliJ-based IDEs.