feat: add main and vocabulary text

main.py

@@ -0,0 +1,30 @@
+import math
+import random
+
+class Neuron:
+    def __init__(self, isize: int) -> None:
+        self.isize = isize
+        self.weight = [random.uniform(0, 1) for _ in range(self.isize)]
+        self.bias = random.uniform(0, 1)
+
+    def forward(self, inputs: list) -> float:
+        assert len(inputs) == self.isize, "error: incorrect inputs number"
+        total = sum(self.weight[i] * inputs[i] for i in range(self.isize)) + self.bias
+        return self.sigmoid(total)
+    
+    def sigmoid(self, x: float) -> float:
+        return 1/(1 + math.exp(-x))
+
+    # target needs to be between 0 and 1
+    def train(self, inputs: list, target: float, learning_rate: float = 0.1):
+        z = sum(self.weight[i] * inputs[i] for i in range(self.isize)) + self.bias
+        output = self.sigmoid(z)
+
+        error = output - target
+        d_sigmoid = output * (1 - output)
+        dz = error * d_sigmoid
+
+        for i in range(self.isize):
+            self.weight[i] -= learning_rate * dz * inputs[i]
+
+        self.bias -= learning_rate * dz