Add Debug image docs

[mathemancer]

This adds a page to the docs describing our new debug-enabled docker image, and its use.

Technical details

The image in question is the same as the production docker image, except both Gunicorn and Django debugging are enabled. It's designed to let us help users more easily with their docker-based Mathesar setups.

Checklist

- [X] My pull request has a descriptive title (not a vague title like `Update index.md`). - [ ] My pull request targets the `develop` branch of the repository - [X] My commit messages follow [best practices][best_practices]. - [X] My code follows the established code style of the repository. - [ ] I added tests for the changes I made (if applicable). - [X] I added or updated documentation (if applicable). - [X] I tried running the project locally and verified that there are no visible errors. [best_practices]:https://gist.github.com/robertpainsi/b632364184e70900af4ab688decf6f53 ## Developer Certificate of Origin

Developer Certificate of Origin

``` Developer Certificate of Origin Version 1.1 Copyright (C) 2004, 2006 The Linux Foundation and its contributors. 1 Letterman Drive Suite D4700 San Francisco, CA, 94129 Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Developer's Certificate of Origin 1.1 By making a contribution to this project, I certify that: (a) The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or (b) The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or (c) The contribution was provided directly to me by some other person who certified (a), (b) or (c) and I have not modified it. (d) I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved. ```

[mathemancer]

@pavish I know you don't have much context here, but I thought you could look through and make sure these new docs are at least coherent since @Anish9901 and @seancolsen are out at the moment.

[mathemancer]

Looks good @mathemancer, I am assuming that we'd need to build this image each time we make a release. So, It would be good to document the build commands under the release process in the wiki. We would also require building and publishing this image to docker hub for this release, could you take responsibility for that?

Yep, will do.

[kgodey]

Yep, will do.

@mathemancer I added Basecamp tasks for:

• Documenting the process for publishing debug images (to the 0.1.6 release project)
• Actually publishing debug images (to the 0.1.6, 0.1.7 release projects, as well as the release template)

Let me know if that seems okay or if there needs to be more or less tracking.