Mention that vec0 tables cannot be renamed

[emschwartz]

This might be obvious to others but it might be worth mentioning in the docs that vec0 tables cannot be renamed.

I was trying to migrate an existing table to use sqlite-vec with the following migration script:

CREATE VIRTUAL TABLE new_item_embeddings USING vec0(
    embedding FLOAT[1024]
);

INSERT INTO new_item_embeddings (rowid, embedding)
SELECT id, embedding FROM item_embeddings;

DROP TABLE item_embeddings;

ALTER TABLE new_item_embeddings RENAME TO item_embeddings;

However, trying to select or insert using that renamed table fails with an error like: Internal sqlite-vec error: could not initialize 'rowids get chunk position' statement.

This migration script works:

ALTER TABLE item_embeddings RENAME TO old_item_embeddings;

CREATE VIRTUAL TABLE item_embeddings USING vec0(
    embedding FLOAT[1024]
);

INSERT INTO item_embeddings (rowid, embedding)
SELECT id, embedding FROM old_item_embeddings;

DROP TABLE old_item_embeddings;

[asg017]

This will be fixed in #43! I'll try to get it in the latest release

[emschwartz]

Ah, nice! Didn't see that PR