Fixed typo in custom-cms-element how-to

[Haberkamp]

1. Why is this change necessary?

For a better documentation

2. What does this change do, exactly?

It changes compoent to component.

3. Describe each step to reproduce the issue or behaviour.

Add an a after the letter o in the word compoent.

4. Please link to the relevant issues (if any).

5. Which documentation changes (if any) need to be made because of this PR?

6. Checklist

• I have written tests and verified that they fail without my change
• I have squashed any insignificant commits
• This change has comments for package types, values, functions, and non-obvious lines of code
• I have read the contribution requirements and fulfil them.

[mitelg]

thanks @Haberkamp for your contribution 👍 🎉 💙

will be merged soon