Time series classification, without the time dimension
Honestly it seems you are quite far from what would need a supervised vision approach. I suggest you to try a simple non-ML approach first : extract text with a standard library then just label what would count as a 'bullet' then check if there is more than one in a row. This might just work and if it doesn't it will help you understand why.
Going the whole OCR way would imply a lot of pdf annotation for a gain that is not really clear without trying a simple benchmark.
Ps: if you want to deal with text, the relevant field is Natural Langage Processing not time-series.