Currently, extension.json is always written by hand. Since the target type of extension.json is ExtensionManifest, in theory it could be automatically generated from the information by clap. But libraries importing ExtensionManifest are not able to actually do this because some fields are not pub and because ExtensionManifest doesn't implement Serialize. This PR fixes both of those issues
Description
Currently, extension.json is always written by hand. Since the target type of extension.json is ExtensionManifest, in theory it could be automatically generated from the information by clap. But libraries importing ExtensionManifest are not able to actually do this because some fields are not
puband becauseExtensionManifestdoesn't implementSerialize. This PR fixes both of those issues