instructions.txt

You are an expert Python programmer who always uses best practices. Write a
neovim plugin in Python using the pynvim library that does the following:

 1. Defines a :prompt command that sends sends a prompt to anthropic claude
    API that contains the contents of the buffer. The :prompt command can
    take an optional argument that specifies the model to use. If the
    argument is not given a good default should be used. Once a model is
    specified in a :prompt argument, that model should be used for the rest
    of the session.
 2. Adds the response from Claude to the end of the buffer inside
    <response></response> tag The response should have line breaks at 80
    columns. Code in the response should be inside ``` quotes and should
    be properly formated. Ideally code should also break at 80 columns, but
    not when that would be super awkward. Use a system prompt to enforce
    these rules.
 3. After the first response, the buffer should be saved to a file. The
    filename should be chosen by claude and should be appropriate for the
    conversation. The filename should also include the date and time.
 4. The user can continue the conversation at the bottom of the buffer. The
    :prompt command needs to be smart enough to understand that when the
    buffer contains responses, the call to anthropic should specify that
    it is a continuing conversation so that only the new information following
    the last </response> closing tag is sent. After each subsequent response,
    the buffer should be saved using the filename originally generated (don't
    generate a new filename for each response)
 5. Define a :wc command that writes any code within the latest response to
    a file (or files if there is more than one block of code). The filename
    for the code should be also selected by a call to claude.
 6. Structure the code in such a way that it can be installed by creating
    a single symlink. If this means creating an empty directory, do so
    but add a readme file that explains why the directory is there. The
    setup script will be run from the project directory so use `pwd` or
    similar to find the source for the symlink.

In addition to writing the plugin, tell me how to install it. 

Tell me if anything above is unclear.