Added comment about hook files and initialization (#6756)

* Added comment about hook files and initialization

* ORMs -> clients

Co-authored-by: Ben McCann <[email protected]>

* Removed redundant wording: run code that runs

* Update documentation/docs/07-hooks.md

Co-authored-by: Ben McCann <[email protected]>
Co-authored-by: Rich Harris <[email protected]>

Author: 3 people

documentation/docs/07-hooks.md

@@ -9,6 +9,8 @@ There are two hooks files, both optional:
 - `src/hooks.server.js` — your app's server hooks
 - `src/hooks.client.js` — your app's client hooks
 
+Code in these modules will run when the application starts up, making them useful for initializing database clients and so on.
+
 > You can configure the location of these files with [`config.kit.files.hooks`](/docs/configuration#files).
 
 ### Server hooks