#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/webbrowser.rst b/Doc/library/webbrowser.rst
index b978777..56c444d 100644
--- a/Doc/library/webbrowser.rst
+++ b/Doc/library/webbrowser.rst
@@ -48,7 +48,7 @@
 The following functions are defined:
 
 
-.. function:: open(url[, new=0[, autoraise=True]])
+.. function:: open(url, new=0, autoraise=True)
 
    Display *url* using the default browser. If *new* is 0, the *url* is opened
    in the same browser window if possible.  If *new* is 1, a new browser window
@@ -178,7 +178,7 @@
 module-level convenience functions:
 
 
-.. method:: controller.open(url[, new=0[, autoraise=True]])
+.. method:: controller.open(url, new=0, autoraise=True)
 
    Display *url* using the browser handled by this controller. If *new* is 1, a new
    browser window is opened if possible. If *new* is 2, a new browser page ("tab")