Update .github/PULL_REQUEST_TEMPLATE.md

Co-Authored-By: Jaro Camphuijsen <[email protected]>

Author: SarahAlidoost

.github/PULL_REQUEST_TEMPLATE.md

@@ -11,7 +11,7 @@ Please keep in mind that lesson maintainers are volunteers and it may be some ti
 - [ ] Create an [issue](https://github.com/ESMValGroup/tutorial/issues) to discuss what you are going to do.
 - [ ] Give this pull request a descriptive title.
 - [ ] If you are contributing to the lesson materials, please make sure the content conforms to the `Lesson development` section in [CONTRIBUTING.md](https://github.com/ESMValGroup/tutorial/blob/master/CONTRIBUTING.md) and does not contain any spelling or grammatical errors. 
-- [ ] Please use a `markdown lint tool` to check that your markdown files do not contain errors, bugs, or stylistic errors.
+- [ ] Please use a `markdownlint` tool to check that your markdown files do not contain errors, bugs, or stylistic errors.
 - [ ] Preview changes on your own machine before pushing them to GitHub by running `make serve`, alternatively `make docker-serve`. Please see the `Previewing your changes locally` section in[CONTRIBUTING.md](https://github.com/ESMValGroup/tutorial/blob/master/CONTRIBUTING.md) for installation instructions.
 - [ ] All code instructions have been tested.