Document the process for adding to the contributors.txt list

[Qchristensen]

Is your feature request related to a problem? Please describe.

Every now and then we get asked about how to be added to the contributors list.

Describe the solution you'd like

Having this process (create a PR requesting it) documented, would be helpful for new and existing contributors.

Describe alternatives you've considered

Additional context

Prompted by an email request on 23/07/2024

[CyrilleB79]

Document not only how to add someone but also who can/should be added.

[gerald-hartig]

After careful consideration, we have decided to archive the contributors.txt file. Here's why:

1. The file has not been consistently maintained or updated
2. The criteria for inclusion in the list have been unclear
3. Many valuable contributors have been inadvertently omitted

Moving forward, we will better recognise contributions through:

• GitHub's built-in contributors list, which automatically tracks code contributions
• Release notes that highlight significant contributions

The existing contributors.txt will be moved to archived/contributors.txt to preserve the historical record while making it clear that it's no longer actively maintained.

References to the file in the code will need to be updated.

[CyrilleB79]

Have you discussed / made any decision regarding how translators contributions are tracked? (and if it should be)

[seanbudd]

Reports which track translations similar to the github contribitors page are currently available in Crowdin to NV Access via Crowdin Top Members reporting