Fix docstring for css_first method

It actually accepts any type.

Author: rushter

selectolax/lexbor.pyx

@@ -192,7 +192,7 @@ cdef class LexborHTMLParser:
         ----------
 
         query : str
-        default : bool, default None
+        default : Any, default None
             Default value to return if there is no match.
         strict: bool, default True
             Set to True if you want to check if there is strictly only one match in the document.

selectolax/lexbor/node.pxi

@@ -204,7 +204,7 @@ cdef class LexborNode:
         ----------
 
         query : str
-        default : bool, default None
+        default : Any, default None
             Default value to return if there is no match.
         strict: bool, default True
             Set to True if you want to check if there is strictly only one match in the document.

selectolax/parser.pyx

@@ -72,7 +72,7 @@ cdef class HTMLParser:
         ----------
 
         query : str
-        default : bool, default None
+        default : Any, default None
             Default value to return if there is no match.
         strict: bool, default True
             Set to True if you want to check if there is strictly only one match in the document.