Last correction to the notebook to get rid of a useless intermediate output, graph adjacency matrix object

Add lines on useful resources to answer to the question and first line on describing the first step to perform.

Move forward on graphic for question 2 lack of few lines of code to write text in the figure properly

move forward on question 2 answer and bar plots but some corrections need to be done with names of personnages.

add work on file parsing taking into account specific cases encountered in the text of the theatre piece

corrections of problems with startswith, replacement by working regex to detect acts and scenes lines

Update jupyter notebook flue_syndrome_incidence_analysis with work of exo1 of module 3 + correction of 'inc' column data type