give better intuition for neural networks

- neural networks to solve xor/xnor

- better to add value to the edges of the graph to help better visualize
- the truth table works with disabling(multiplied by zero)
- in the end, the result is the same as AND truth table

- 0 0 = -10 (0)
- 0 1 = 10 (1)
- 1 0 = 10 (1)
- 1 1 = 30 (1)
- works like OR truth table

- these are neural networks solving logical base truth table function
- next discuss about multiple layer of units solving xor/xnor function