Update READMEs, github descriptions, and github features on Islandora-Devops

[rosiel]

This was discussed in today's tech call.

In various Islandora-Devops repos,

• it may be hard to tell based on READMEs and/or descriptions what these repositories are and how they should (or not) be used. (e.g. islandora-sandbox, looks like at least one person tried to install it directly!)
• some repositories have Issue queues open, which are not monitored by the tech call. Some of these issue queues have issues in them. (e.g. islandora-sandbox, sorry bout that)
• Some repositories (islandora-project) should be deprecated.

Descriptions, issue queues, and deprecation needs to be done by someone with owner powers.

I can make Readme PRs when I have more context.

Repos in question:

https://github.com/Islandora-Devops/islandora-sandbox
https://github.com/Islandora-Devops/islandora_starter_theme
https://github.com/Islandora-Devops/islandora_install_profile_demo
https://github.com/Islandora-Devops/islandora_base_theme
https://github.com/Islandora-Devops/islandora-project
https://github.com/Islandora-Devops/islandora_profile

[rosiel]

Further to this:

Since the merge of Islandora-Devops/islandora-playbook#201, all the ansible roles are deprecated as individual repositories.

However, their READMEs are very out of date (citing Xenial and CentOS) and need to be updated.