tweak docs related to dev local environment setup (#5434)

* remove outdated config file description

`example_config.json` was removed in f11da7b05b but the documentation
was still there, this removes the description from the README as well.

* add a note about how to use scripts with premium features

docs/Contributing/Seeding-Data.md

@@ -43,4 +43,6 @@ The `fleet/create_figma` script will generate an environment to reflect the mock
 
 Each user generated by the script has their password set to `user123#`.
 
+In order to run scripts that make use of premium features, make sure you started the server with the correct flags as described in [Testing](./Testing.md#license-key).
+
 <meta name="pageOrderInSection" value="600">

tools/osquery/README.md

@@ -4,8 +4,6 @@ The files in this directory are intended to assist with Fleet development.
 
 - `docker-compose.yml`: This docker-compose file helps with starting `osqueryd` instances for testing Fleet. More on this [below](#testing-with-containerized-osqueryd).
 
-- `example_config.json`: An example config file with insecure default passwords. Useful for testing in a local dev environment, but should /never/ be used in production.
-
 - `example_osquery.conf`: An example osquery config file that sets up basic configuration for distributed queries.
 
 - `example_osquery.flags`: An example osquery flagfile setting the config options that must be loaded before the full JSON config.