Add customisations.md file to capture customisations

[Kristina Hoeppner]

Documentation is important, but updating the regular Mahara README file can lead to merge conflicts. Therefore, setting up a CUSTOMISATIONS file that is linked to from the README can help with that. While it wouldn't be the default file viewed when a repo is opened, it's easily accessible and can capture site specific information rather than keeping that in a separate document.

It would sit outside of the htdocs directory so it isn't deployed to a server when a site is installed. Because the file is committed into the repo so others working on the repository have access to it, it needs to be in Git rather than be ignored. Therefore, it should not contain sensitive information such as passwords or personal info.

[Mahara Bot (dev-mahara)]

Patch for "main" branch: https://reviews.mahara.org/c/mahara/+/13100

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/c/mahara/+/13100
Committed: https://git.mahara.org/mahara/mahara/commit/a304c2aa3956856660e765a4f8c19824e2d44629
Submitter: "Robert Lyon <email address hidden>"
Branch: main

commit a304c2aa3956856660e765a4f8c19824e2d44629
Author: Kristina Hoeppner <email address hidden>
Date: Fri Aug 26 14:35:18 2022 +1200

Bug 1987718: Add customisations file to capture site-specific documentation

Change-Id: I16ac6d8e9df28abe32f46a4ee40e1380023839d0