This is intended to be a replacement for Mojang's version_manifest_v2.json that includes more versions, more data for all versions, and is consistent as to how data is formatted across all versions. It can be accessed at https://meta.omniarchive.uk/v1/manifest.json.
The main manifest JSON references individual version JSONs.
JSON schemas for both manifest and version files can be found here and here, respectively.
These links can also be found in the $schema field where applicable.
If you have any feedback or bug reports, please open an issue in this repository. Issues that are not related to the manifest itself will be closed.