[Feature Request] Possibility to add and remove "appears in chapters" entries

[Lobz]

Manually adding appearances would be useful for when the character appears but isn't named. Using aliases isn't enough because "a woman" could be referring to the character "Mary" in chapter 1, and to the character "Lilah" in chapter 5.

Removing appearances would be useful for when the automatic detection makes a mistake; for example, when two locations have the same name. For instance, "the TARDIS" is a different location from "the Master's TARDIS", but the software doesn't know how to tell them appart.