Applied fixes by @bschussek
feature #3517 Fixed OptionsResolver component docs (WouterJ)

This PR was merged into the 2.3 branch.

Discussion
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Fixed OptionsResolver component docs

I finally applied the comments of https://github.com/symfony/symfony-docs/pull/2547#issuecomment-16993740

| Q   | A
| --- | ---
| Doc fix? | yes
| New docs? | no
| Applies to | 2.1+
| Fixed tickets | https://github.com/symfony/symfony-docs/pull/2547#issuecomment-16993740

Commits
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0e9a474 Applied fixes by @bschussek