When linking to an index page, explicitly name index.html instead of

using "./".  The later does not work nicely when browsing docs on a local
disk (as in the installed docs on Windows).

Doc/tools/support.py

@@ -25,7 +25,7 @@ class Options:
     outputfile = "-"
     columns = 1
     letters = 0
-    uplink = "./"
+    uplink = "index.html"
     uptitle = "Python Documentation Index"
 
     def __init__(self):