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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def rstjinja(app, docname, source):
 """ Render our pages as a jinja template for fancy templating goodness. """

    # Make sure we're outputting HTML
    if app.builder.format != 'html':
        return
    src = source[0]
    rendered = app.builder.templates.render_string(
        src, app.config.html_context
    )
    source[0] = rendered