Documentation is missing for for_all_sites

[DonRichards]

"for_all_sites" is used several times throughout the makefile but there is no documentation on what it is and how to use it.

Once the drupal container is built there is a script "/etc/islandora/utilities.sh"

There is no obvious indication it comes from the [isle-buildkit](https://github.com/Islandora-Devops/isle-buildkit/blob/main/drupal/rootfs/etc/islandora/utilities.sh) and needs documentation.

Related ticket: #134

Code Comments (dump)

This needs some context but can stand in for some basic information of the behavior from this script.

1. Capitalize the given string.
2. Transform the given string to uppercase.
3. Joins the given array into a string delimited by the first argument.
4. Get variable value for given site.
5. Get the index of the given site in the lists of site. Useful for generating distinct identifiers.
6. Wait for service to respond.
7. Waits for services that are required to be running to successfully ingest content.
8. Apply given function for all sites in parallel, up to the number of cores available.
9. Create a database for the given site.
10. Install the given site.
11. Get the base url of fedora.
12. Allow modifications to settings.php by changing ownership and perms
13. Restore ownership of settings.php so that it is readable/writable outside of docker
14. Regenerate / Update settings.php
15. Enable module and apply configuration.
16. Install and configure the islandora module.
17. After enabling and importing features a number of configurations need to be updated.
18. Install search_api_solr and configure. Also uninstall the default search module.
19. Enables and sets carapace as the default theme.
20. Generate solr config using the search_api_solr module. Assumes the search_api_solr module has already been installed. Assumes that the destination will be a shared volume.
21. Creates a SOLR core for the site using the Solr REST API.
22. Generate solr config and create a core for it.
23. Install matomo and configure.
24. Configure Openseadragon to point use cantaloupe.
25. Imports any migrations in the 'islandora' group.
26. Enable module and apply configuration.
27. Enable module and apply configuration.
28. Rebuild the cache for the given site.
29. Changes the site ID to match the configuration folder to allow it to be imported.
30. Replace references to standard profile in the config files with minimal. Often we build sites with the standard profile but it is not possible to install from a configuration that was generated on a standard profile site.
31. Import sites configuration.
32. Export sites configuration.
33. Generates blazegraph properties for the given site using its namespace.
34. Create a namespace with the given properties file.
35. Create a namespace with default properties for the given site.