Fix curl example command to include quotes around url

What does this MR do?

Add qoutes to one particular example command on the gitlab runner docs i encountered issues with.

Why was this MR needed?

The characters < and > are present in the url, these are special characters in bash and are unescaped.

Are there points in the code the reviewer needs to double check?

Does this MR meet the acceptance criteria?

• Documentation created/updated
• Added tests for this feature/bug
• In case of conflicts with master - branch was rebased

What are the relevant issue numbers?

None