Add SpatiaLite helpers to CLI #398
Description
Now that #385 is merged, add CLI versions of those methods.
# init spatialite
sqlite-utils init-spatialite database.db
# or maybe/also
sqlite-utils create database.db --enable-wal --spatialite
# add geometry columns
# needs a database, table, geometry column name, type, with optional SRID and not-null
# this needs to create a table if it doesn't already exist
sqlite-utils add-geometry-column database.db table-name geometry --srid 4326 --not-null
# spatial index an existing table/column
sqlite-utils create-spatial-index database.db table-name geometryShould be mostly straightforward. The one thing worth highlighting in docs is that geometry columns can only be added to existing tables. Trying to add a geometry column to a table that doesn't exist yet might mean you have a schema like {"rowid": int, "geometry": bytes}. Might be worth nudging people to explicitly create a table first, then add geometry columns.