* [webpack] add compilation.addChunkInGroup method Links: - https://github.com/webpack/webpack/blob/v4.42.1/lib/Compilation.js#L1485 * [webpack] add mainTemplate.hooks.afterStartup and hashForChunk typings Links: - https://github.com/webpack/webpack/blob/v4.42.1/lib/MainTemplate.js#L102 - https://github.com/webpack/webpack/blob/v4.42.1/lib/MainTemplate.js#L127 * [webpack] add compilation.ChunkGroup typings Links: - [chunks](https://github.com/webpack/webpack/blob/v4.42.1/lib/ChunkGroup.js#L70) - [childrenIterable](https://github.com/webpack/webpack/blob/v4.42.1/lib/ChunkGroup.js#L240) - [parentsIterable](https://github.com/webpack/webpack/blob/v4.42.1/lib/ChunkGroup.js#L281) - [insertChunk](https://github.com/webpack/webpack/blob/v4.42.1/lib/ChunkGroup.js#L158) - [getNumberOfChildren](https://github.com/webpack/webpack/blob/v4.42.1/lib/ChunkGroup.js#L236) - [module index methods](https://github.com/webpack/webpack/blob/v4.42.1/lib/ChunkGroup.js#L456-L492) - [addChild](https://github.com/webpack/webpack/blob/v4.42.1/lib/ChunkGroup.js#L224) - [removeChild](https://github.com/webpack/webpack/blob/v4.42.1/lib/ChunkGroup.js#L244) - [setParents](https://github.com/webpack/webpack/blob/v4.42.1/lib/ChunkGroup.js#L266)
