Add !find command to help with finding pokemon you've already caught

Summary

Add a !find command that allows searching for specific pokemon instead of combing through the !list command.

Closes #1 (closed)

Testing

Test 1: Caught the first pokemon but missing evolutions

Test 2: Caught a pokemon with no evolutions

Test 3: Caught a pokemon and evolution but missing another evolution

Test 4: Specified wrong pokemon

Test 5: Specified pokemon trainer has not caught