Spyder IDE cell support

[MarcusJones]

Just hacked this together for Spyder - shall I make a PR? Is this project still active? Inside def convert_toplevel_docstring(tokens):

        elif token.type == tokenize.COMMENT:
            text = token.string
            if text.startswith('#%%'):
                #print("Spyder cell")
                startline, startcol = token.start
                # Starting column MUST be 0
                if startcol == 0:
                    endline, endcol = token.end
                    lines = [line
                             for line in text.strip('"\' \n').split('\n')]
                    assert len(lines) == 1
                    text = '\n'.join(lines)
                    #text = text[3:]
                    text = text.replace("#%%", "") 
                    text = text.lstrip()
                    fmt = '# <markdowncell>\n{0}\n# <codecell>'.format(text)
                    res = TokenInfo(type=tokenize.COMMENT,
                                    start=(startline, startcol),
                                    end=(endline, endcol),
                                    string=fmt,
                                    line='#')
                    yield res
                    # To next token
                    continue