Bumped spellcheck GitHub action to version 0.20.0
Bumped spellcheck GitHub action to version 0.20.0

I have recently released 0.20.0 of the spellcheck GitHub action, I can see that you are using 0.16.0, so an update could be useful to you. Let me know if you have any issues with the proposal and I will try to accommodate.

I can recommend [Dependabot](https://github.com/dependabot) for keeping your GitHub actions up to date, if you want a PR proposing a basic configuration, please let me know.
webbukkit/dynmap,webbukkit/dynmap,webbukkit/dynmap,webbukkit/dynmap