More robust (multiline) notes

**Is your feature request related to a problem? Please describe.**
It would be good to have more robust, multiline notes that can be edited in a CLI editor (e.g., vim).

**Describe the solution you'd like**
I'd like to be able to create and edit notes and have it launch my preferred editor (e.g., vim) to edit. The taskboard view would only show the first line (and perhaps only N characters of it) followed by some notation to indicate there is more text not shown in the taskboard view (e.g., an ellipsis: "...").

**Additional context**
Add an entry in the `~/.taskbook.json` file for `defaultEditor`. For this example, I will assume vim.

Example workflow:

tb -n @thisismyboard

Launches vim with blank note.

tb -e @2

Launches vim with current text of note with id 2 populated.

Start at the CLI handling for `tb -n` and `tb -e`, then inspect how `~/.taskbook.json` is read and how notes are rendered in the taskboard view. Done means notes can be created and edited through the configured editor, multiline text is preserved, and the board shows only the first line with an indication when more text exists.

Written by the indexing model from the issue text.