Update README file for "plain language" feature

The README file needs to be update to reflect to "plain language" feature. Here's a rough draft for now:

If you want to see all the nodes in a particular term in a particular term,
you'd type:

www.site.com/typecat/alias/vocabulary/term

You can go as many levels deep as you like, for example:
www.site.com/typecat/alias/vocabulary/term1/term2/term3/term4

You can also do an abbreviated version and not include the vocabulary:
www.site.com/typecat/alias/term

Note that if you have two categories with the same term name, it will print
nodes from both categories. Note that this also prints all the nodes in
subcategories of this node, too. If you want just the the nodes in the
category and not in the subcategories, use the long version above. (Perhaps
it should be just the opposite and the short version should only produce
nodes in that term?)

If you want to print all the nodes in a particular vocabulary, do this:
www.site.com/typecat/alias/vocabulary/0

'0' means print all the nodes in that vocabulary. (Until I find a better
way, the user must be advised not to name a term '0')

Yes, the module handles spaces in the name of the category. I don't know
about other characters. I haven't tested it yet. No, the program won't
choke if the user has identical paths to a term, it will return nodes from
both of the terms. For example, even if the user had identical vocabulary
structures like this:

Fruits
-Apples
--Green
---Rotten

Fruits
-Apples
--Green
---Rotten

and supplied 'fruits/apples/green/rotten' for the path, it would pull nodes
from both "Rotten" categories.