Fixed typos in docstring and comment in README.rst and fourigui.py

[Fil158]

Fixed 1 typo in README.rst
Fixed 1 typo in fourigui.py

[bobleesj]

@Fil158 Please clean your commit history by making a new branch off of 'main' and make sure you run pre-commit before making a PR

You can close this

[bobleesj]

For minor typos, you don't need to make news moving forward since it's not useful info in changelog.rst

[bobleesj]

@Fil158 I created a new GitLab page: Lessons from Prof. Simon Billinge which you can find it directly or linked in the Group workflow page.

Please check the GitHub pull request tips section carefully in the following PRs so that we can streamline the process.