readme update

See merge request !24

Export indexers

See merge request !23

Schema extension

See merge request memri/schema!22

Export indexers

See merge request memri/schema!21

added sha256

See merge request memri/schema!20

Schema export indexers

See merge request memri/schema!19

Update File and add Resource

See merge request memri/schema!18

Rename PublicKey to CryptoKey and add some fields

See merge request memri/schema!17