positive235

Removed unnecessary comments in the source codes

2

Checklist: - [x] I have read [freeCodeCamp's contribution guidelines](https://contribute.freecodecamp.org). - [x] My pull request has a descriptive title (not a vague title like `Update index.md`) - [x] My pull request...

Added options for the types of activation functions - tanh function or sigmoid function. In both cases, the code achieves 100.0% accuracy for the XOR classification problem.