Update graphQL documentation to capture new directives

[pxp928]

Once the new release is done and PR guacsec/guac#1610 is released, the graphQL documentation needs to be updated to include contains and startsWith custom graphQL directives that can be used in queries.

For example:

query ArtifactsQ1 {
  artifacts(artifactSpec: {}) @filter(keyName: "digest", operation: STARTSWITH, value: "322") {
    algorithm
    digest
  }
}

Issue guacsec/guac#1615 has been created to do the same for nested fields