Add defaults to hookspec and fix empty problem, add readme

README.md

 # Catlizor (v1)
 Action Hooks
+
+## Example
+```py
+from catlizor import Hook, Catlizor
+
+class TaskManager:
+    def __init__(self):
+        self.tasks = {}
+        
+    def add_task(self, task: str, *items):
+        self.tasks[task] = items
+        
+    def pop_task(self):
+        return self.tasks.popitem()
+    
+    def get_tasks(self, task: str):
+        return self.tasks[task]
+        
+@Hook.pre
+class PreLoggingHook(Hook):
+    methods = ['add_task']
+    callbacks = [lambda result: print(result.args, result.kwargs)]
+
+@Hook.on_call
+class PostLoggingHook(Hook):
+    methods = ['pop_task', 'get_tasks']
+    callbacks = [lambda result: print(result.result)]
+
+tm_catlizor = Catlizor.hook(TaskManager, PreLoggingHook, PostLoggingHook)
+tm = TaskManager()
+tm.add_task("süt al", "markete git", "süt reyonuna ulaş")
+tm.get_tasks("süt al")
+tm.pop_task()
+```
+
+Result (stdout);
+```
+(<__main__.TaskManager object at 0x7fa851743748>, 'süt al', 'markete git', 'süt reyonuna ulaş') {}
+('markete git', 'süt reyonuna ulaş')
+('süt al', ('markete git', 'süt reyonuna ulaş'))
+```
+```

catlizor/catlizor.py

@@ -2,7 +2,7 @@ from __future__ import annotations
 
 from collections.abc import Sequence as SequenceBase
 from contextlib import contextmanager
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from enum import Enum, auto
 from functools import partial, reduce, wraps
 from types import FunctionType
@@ -18,7 +18,7 @@ def get_hooks(cond, hooks: Tuple[Sequence[Hook], ...]):
 
     res = sum(getattr(hook, HOOK_SPEC) for hook in filter(compare_hook, hooks))
     if res == 0:
-        res = HookSpec(None, None)
+        res = HookSpec()
     return res
 
 
@@ -42,8 +42,8 @@ class Result:
 
 @dataclass
 class HookSpec:
-    methods: Optional[Sequence[str]]
-    callbacks: Optional[Sequence[Callable]]
+    methods: Optional[Sequence[str]] = field(default_factory=set)
+    callbacks: Optional[Sequence[Callable]] = field(default_factory=set)
 
     def __post_init__(self):
         for attr in vars(self).keys():