updated index.d.ts to support return types for Signin and Signout Response
updated index.d.ts to support return types for Signin and Signout Response

IdentityModel/oidc-client-js,IdentityModel/oidc-client-js,IdentityModel/oidc-client-js,IdentityModel/oidc-client,IdentityModel/oidc-client,IdentityModel/oidc-client