add support for graphiql 2.0

[debu999]

With upgrade to graphiql 2.0 can there be udpate to graphiql-explorer to support 2.x version. currently it does not work well on graphiql 2.0 need help to upgrade it to graphiql 2.x

[acao]

@debu999 you can use the provided graphiql@2 plugin here:

https://github.com/graphql/graphiql/tree/main/packages/graphiql-plugin-explorer