Add words "Optimist", "Pessimist" and "Pessimistic"

[Showndarya]

Add words Optimist, Pessimist and Pessimistic

Add all the definitions of Optimist in a file named Optimist.json
Add all the definitions of Pessimist in a file named Pessimist.json
Add all the definitions of Pessimistic in a file named Pessimistic.json

Refer Contribution.md for more details on how to contribute.

Comment here if you're are working on this issue to avoid conflicts.
Add reference to this issue i.e Issue #235 in your pull request description.

[dionisioC]

Let me check this

[unrooted]

Check my PR @Showndarya