Create and diaplay a list of first characters for post/cpt titles which link to an archive of the posts/cpts that begin with that character.
This widget will get a list of post/cpt title first character. The list is then displayed as an unordered list of links. The links take the user to an archive page for the specific post type and display the posts where its title begins with the character.
If the title begins with the following words, the first character of the second word will be used: