Fixed the default stack id

.changeset/lazy-pillows-leave.md

@@ -0,0 +1,5 @@
+---
+"stackid": patch
+---
+
+Fixed the default stack id

README.md

@@ -22,14 +22,14 @@ import { createStack } from 'stackid';
 // Create a stack
 const stack = createStack();
 
-const id1 = stack.pushStack(); // Pushes a new identifier (e.g., 0)
-const id2 = stack.pushStack(); // Pushes another identifier (e.g., 1)
+const id1 = stack.pushStack(); // Pushes a new identifier (e.g., 1)
+const id2 = stack.pushStack(); // Pushes another identifier (e.g., 2)
 
 console.log(stack.onTopStack(id2)); // true
 
 stack.popStack(id2); // Pops the identifier from the stack
 
-console.log(stack.getState()); // [0]
+console.log(stack.getState()); // [1]
 ```
 
 ### Managing the stack

src/index.ts

@@ -1,5 +1,5 @@
 function genNextId<T>(prev?: T): T {
-  return (typeof prev === 'number' ? prev + 1 : 0) as T;
+  return (typeof prev === 'number' ? prev + 1 : 1) as T;
 }
 
 export function createStack<T = number>(nextId?: (prev?: T) => T) {