Add Github action for README.md spell check

[sarroutbi]

Resolves: #22

[sunner]

It seem that the check prevented itself?

[sarroutbi]

Yes. I updated the allowed word list and fixed another typo in README.md. That should be enough.

[sunner]

O.....it failed again. Could you just PR the modification of README.md ? The spell check is beautiful, but I'm afraid that it will block many normal commits.

[sarroutbi]

I prefer keeping it. README.md is normally not modified, so this won't affect once it passes. As you can see, only a pair of words are failing.

[sunner]

But README always has new strange words such as name of new models. And wrong spells don't occur always.

[sarroutbi]

OK. I will upload only fix for typos. Thanks for your review.

[sunner]

Thank you! You let me know the spell check service. Someday, I will get something good from it.