Clean-up usage of root directory in docs generation

Instead, make use of the current working directory.
This should ease most of it and remove noise, since
now root is just the current directory.

telethon_generator/docswriter.py

@@ -6,12 +6,11 @@ class DocsWriter:
     """
     Utility class used to write the HTML files used on the documentation.
     """
-    def __init__(self, root, filename, type_to_path):
+    def __init__(self, filename, type_to_path):
         """
         Initializes the writer to the specified output file,
         creating the parent directories when used if required.
         """
-        self.root = root
         self.filename = filename
         self._parent = str(self.filename.parent)
         self.handle = None