Update CONTRIBUTING.md (krzjoa#25)

Author: Prathu121

CONTRIBUTING.md

@@ -5,5 +5,5 @@ If you came here, I suppose you would like to add a lib this list. To do it well
 2. If does, add this lib in the relevant section at the last positionn. Bear in mind, that in many cases one library may fit multiple categories. Choose exactly one, to not duplicate contents.
 3. Obviously, check if the library does not occur in the list!
 4. Adorn with coresponding icon(s) if possible (such as sklearn, TensorFlow and so on).
-5. Desctiption should start with a capital letter and be ended with proper punctuation.
+5. Description should start with a capital letter and be ended with proper punctuation.
 6. Feel free to propose any other changes in the list. New section? Removing an item? No problem, we'll think about it :sunglasses: