Changing command to use underscores, per Martin and Tushar

Author: dwicinas

advocacy_docs/pg_extensions/wait_states/installing.mdx

@@ -27,7 +27,7 @@ To install EDB Wait States on any Linux operating system except Debian or Ubuntu
 
       | Type of Postgres distribution | Install command                             |
       | ----------------------------- | ------------------------------------------- |
-      | PostgreSQL                    | postgresql`<version>`-edb-wait-states       |
+      | PostgreSQL                    | postgresql`<version>`-edb_wait_states       |
       | EDB Postgres Advanced Server  | edb-as`<version>`-server-edb_wait_states    |
       | EDB Postgres Extended Server  | edb-postgresextended`<version>`-wait-states |