Fix example step 2 code in README.md

[mfila]

Aligned the code in README.md with the one used in example.js.

[fuzzie360]

Thanks for this @mfila, and sorry it sat for so long.

Your fix is correct. I verified it: on master the step 2 snippet passes the weights coords to .at() and the filter coords to .add(), which is backwards — .at() indexes the 2×2 parent out of bounds and throws. With your swap the snippet reproduces the README's own documented output byte-for-byte.

It turned out there was a second defect in the same snippets that this didn't cover: both reference filter.length, but no filter variable is ever defined, so the code still throws a ReferenceError on paste. Rather than merge and then immediately patch on top, I've folded your change together with that fix into #2, which also covers the security and CI work for this repo. Your commit is credited in the message there.

Closing this as incorporated — the fix is yours, it just ships via #2. Thanks again for reporting it.