Regarding "Installing EDB Wait States"

[lucianobotti]

Summary

We detected an issue in a support ticket which turn out in the following Jira case:
https://enterprisedb.atlassian.net/browse/DC-977

Basically we need to document the need of a grants usage if the extension is created in a another schema.
I'm proposing something like this:

---

Custom schema installation

In case of installing the extension in a non-default schema, it is the user responsability to configure
and grant the specific priviledges for the roles and users.

For example, when installing in a new schema, the pg_monitor role needs to be granted for the usage on the new schema
to be able to properly use the edb_wait_states extension functions:

CREATE EXTENSION edb_wait_states WITH SCHEMA myschema;
GRANT USAGE ON SCHEMA myschema TO pg_monitor;

---

Where would you like to see this added?

https://github.com/EnterpriseDB/docs/blob/main/advocacy_docs/pg_extensions/wait_states/installing.mdx

I think a new section paragraph before 'Uninstalling' would be good.

Rationale

Some customers already faced this issue, hence is necessary to add this documentation.