That's a good idea. We already feature example sentences for a new word from the list every week day (Word of the Day).
If anybody would like to participate, we have simple tools for you to enter example sentences for new words.
However, we always double-check the examples to assure accuracy and we mention you in the credits.
If you insist on wiki, we can help as much as we can and set up one on MasterRussian.org