doc(README): cleanliness for

Author: emptybutton

README.md

@@ -3,7 +3,7 @@ Library for dynamic functional programming and more.
 
 Enter this command and go to the [documentation](https://github.com/TheArtur128/Act/blob/main/DOCS.md):
 ```
-pip install act4==3.1.0
+pip install act4
 ```
 
 ### Overview
@@ -28,9 +28,9 @@ WithDivision = type(division=D)
 Result = WithMultiplication[N] & WithDivision[N]
 
 
-@fbind_by(... |then>> on(None, bad("undefined")))
+@fbind_by(... |then>> on(None, bad("something is missing")))
 @do(maybe, optionally, for_input=optionally)
-def main(do: Do, a: WithNumber[Optional[int]], b: WithNumber[Optional[int]]) -> Result[int]:
+def func(do: Do, a: WithNumber[Optional[int]], b: WithNumber[Optional[int]]) -> Result[int]:
     maybe, optionally = do
 
     first_number = optionally.same(a.number)
@@ -42,16 +42,16 @@ def main(do: Do, a: WithNumber[Optional[int]], b: WithNumber[Optional[int]]) ->
     return Result(multiplication, division)
 
 
-# As a result, `main` has this type.
-main: Callable[
+# As a result, `func` has this type.
+func: Callable[
     [Optional[WithNumber[Optional[int]]], Optional[WithNumber[Optional[int]]]],
     Result[int] | bad[str],
 ]
 
-assert main(WithNumber(16), WithNumber(2)) == obj(multiplication=32, division=8)
-assert main(WithNumber(16), WithNumber(0)) == bad("division by zero")
-assert main(WithNumber(16), WithNumber(None)) == bad("undefined")
-assert main(WithNumber(16), None) == bad("undefined")
+assert func(WithNumber(16), WithNumber(2)) == obj(multiplication=32, division=8)
+assert func(WithNumber(16), WithNumber(0)) == bad("division by zero")
+assert func(WithNumber(16), WithNumber(None)) == bad("something is missing")
+assert func(WithNumber(16), None) == bad("something is missing")
 
 
 class RawResult: