Minor rules text updates + accessibility improvements.

• Properly tagged images in the pdf. Frustratingly, affinity publisher doesn't seem to have reading order tools, so that will have to wait as I can't find an alternative way to do it, apologies.
• Clarified the ending the game text. When a suspect is accused for the 3rd time, the players choose whether to end the game or reveal a scandal proving that suspects innocence and keep playing.
• Clarified the challenge text for the investigator and the example turn.
• Updated the text only version to reflect the changes.