The `reading_list` table has a couple somewhat ad hoc fields like color or icon. Changing the DB schema for those fields is easy before hitting production but will become more troublesome after that. We should probably nail down the semantics now. The current semantics are (note that everything here is in bytes; most non-ASCII characters take two bytes, some might take three):
* name: 255 bytes
* description: 767 bytes
* color: 6 bytes (also, no fixed dictionary of colors)
* image: 255 bytes (unclear if this will be an URL or Commons file name or something else)
* icon: 32 bytes (unclear if this will be an URL or Commons file name or a predefined dictionary or something else)
(Also, `rle_title` needs to be larger to account for the namespace. This does not need to be finalized, just done, but it can be done in the same batch of updates.)