#14804: Remove [] around optional arguments with default values

Mostly just mechanical removal of []. In some rare cases I've pulled the
default value up into the argument list.
diff --git a/Doc/library/pyclbr.rst b/Doc/library/pyclbr.rst
index 2f81451..13eaabf 100644
--- a/Doc/library/pyclbr.rst
+++ b/Doc/library/pyclbr.rst
@@ -19,7 +19,7 @@
 modules.
 
 
-.. function:: readmodule(module[, path=None])
+.. function:: readmodule(module, path=None)
 
    Read a module and return a dictionary mapping class names to class
    descriptor objects.  The parameter *module* should be the name of a
@@ -28,7 +28,7 @@
    of ``sys.path``, which is used to locate module source code.
 
 
-.. function:: readmodule_ex(module[, path=None])
+.. function:: readmodule_ex(module, path=None)
 
    Like :func:`readmodule`, but the returned dictionary, in addition to
    mapping class names to class descriptor objects, also maps top-level