Fix type for postinstall documentation (#5955)

**What's the problem this PR addresses?**
<!-- Describe the rationale of your PR. -->
<!-- Link all issues that it closes. (Closes/Resolves #xxxx.) -->

Grammar issue in documentation

...

**How did you fix it?**
<!-- A detailed description of your implementation. -->
Updated and fixed the line in the doc.
...

**Checklist**
<!--- Don't worry if you miss something, chores are automatically
tested. -->
<!--- This checklist exists to help you remember doing the chores when
you submit a PR. -->
<!--- Put an `x` in all the boxes that apply. -->
- [ ] I have read the [Contributing
Guide](https://yarnpkg.com/advanced/contributing).

<!-- See
https://yarnpkg.com/advanced/contributing#preparing-your-pr-to-be-released
for more details. -->
<!-- Check with `yarn version check` and fix with `yarn version check
-i` -->
- [ ] I have set the packages that need to be released for my changes to
be effective.

<!-- The "Testing chores" workflow validates that your PR follows our
guidelines. -->
<!-- If it doesn't pass, click on it to see details as to what your PR
might be missing. -->
- [ ] I will check that all automated PR checks pass before the PR gets
reviewed.

packages/docusaurus/docs/advanced/02-package-management/lifecycle-scripts.md

@@ -38,7 +38,7 @@ It is guaranteed to be called in topological order (in other words, your depende
 For backwards compatibility, the `preinstall` and `install` scripts, if presents, are called right before running the `postinstall` script from the same package. In general, prefer using `postinstall` over those two.
 
 :::caution
-Postinstall scripts have should be avoided at all cost, as they make installs slower and riskier. Many users will refuse to install dependencies that have `postinstall` scripts. Additionally, since the output isn't shown out of the box, using them to print a message to the user will not work as you expect.
+Postinstall scripts should be avoided at all cost, as they make installs slower and riskier. Many users will refuse to install dependencies that have `postinstall` scripts. Additionally, since the output isn't shown out of the box, using them to print a message to the user will not work as you expect.
 :::
 
 ## Environment variables