fix(es): mark inner package.json as side-effect free (#4984)
fix(es): mark inner package.json as side-effect free (#4984)

some (older) versions of rollup (like the one we use in react instantsearch) don't look at the root package.json, but only at the closest for sideEffects, and thus this change added in #4971 caused a regression in bundle size (notably from Hogan being included)
algolia/instantsearch.js,algolia/instantsearch.js,algolia/instantsearch.js