Added nix for developer setup (#1379) (#1602)

Tested on brand new machines, made a few minor docs tweaks and adjustments for findings, but generally went well so I'm merging this.

docs/development_setup_notes_nix.md

@@ -0,0 +1,74 @@
+# Boost.org Website
+
+## Overview
+
+A Django based website that will power a new Boost website. See the [documentation](./docs/README.md) for more information about maintaining this project.
+
+Links:
+
+- https://www.stage.boost.cppalliance.org/ - staging
+- https://www.boost.org/ - production
+
+---
+
+## Local Development Setup
+
+This project uses Python 3.11, Docker, and Docker Compose.
+
+This document describes how to set up a development environment using Nix, which is a package manager that allows for reproducible builds and development environments, like a better encapsulated declarative cross-platform Homebrew.
+
+For a basic rundown on Nix, this video could be useful https://www.youtube.com/watch?v=yQwW8dkuHqw
+
+1. Install the following according to the instructions for your platform if not already installed:
+   1. Direnv - https://direnv.net/docs/installation.html (don't install OS packaged version, must be >= 2.35.0) and then configure your shell to add the hook as per the direnv docs.
+   2. Docker Engine
+      * Linux - https://docs.docker.com/engine/install/
+      * MacOS - https://orbstack.dev/ or https://github.com/abiosoft/colima ?
+      * Windows - ?
+   3. Just - https://just.systems/man/en/packages.html
+   4. Nix - https://nixos.org/download/ (multi-user, y to all options)
+2. Ask Sam to provide permissions on the database backup drive to an email address associated with Google that you provide.
+3. Clone this https://github.com/boostorg/website-v2.git repository to your machine.
+4. cd into the repository directory.
+   * This should trigger a process which has you to log in to your google account to allow permissions for the production database load later. Use the email address provided to Sam in point 2.
+5. In a terminal run `just bootstrap-nix` in the root of the checked out repository to install the necessary development dependencies and generate the .env file.
+6. Update the generated .env file with the necessary environment variables. Where you can't retrieve these yourself, you can ask someone for some in #boost-website on the slack server at https://ccplang.slack.com. The minimum that must be set is:
+   * GITHUB_TOKEN - a personal access token for the GitHub API, from your profile
+   * STATIC_CONTENT_AWS_ACCESS_KEY_ID - ask for this
+   * STATIC_CONTENT_AWS_SECRET_ACCESS_KEY - ask for this
+7. Run `just setup` to build services, and build the JS and CSS assets. If docker fails with permissions errors, reboot your machine.
+8. Run `just load_production_data` to download live data from the backup server for the website and mailman/hyperkitty. That script can be run regularly to update data from the live servers. You will lose all local data.
+9. Run `docker compose up` to start the server.
+
+
+## Debugging
+For local development there is Django Debug Toolbar, and the option to set a debugger.
+
+In your env:
+- Django Debug Toolbar, enabled by default, can be disabled by setting DEBUG_TOOLBAR=False
+- IDE Debugging, disabled by default, can be enabled by uncommenting `PYTHONBREAKPOINT` in your .env file.
+
+### Set Up Pycharm
+You can set up your IDE with a new "Python Debug Server" configuration as:
+
+<img src="images/pycharm_debugger_settings.png" alt="PyCharm Debugger Settings" width="400">
+
+### Debugger Usage
+To use the debugger add `breakpoint()` on a line in the code before you want to start debugging and then add breakpoints by clicking on the gutter. The debugger will stop at these point, you can then step/inspect the variables.
+
+## Troubleshooting
+
+### Docker
+Keep in mind if there are issues with docker that the host docker daemon on your machine and the docker daemon in the nix setup may not match. It's a good idea to keep both up to date.
+
+### Direnv
+when you switch to the directory you may see direnv exporting a bunch of environment variables as below.
+
+The installer configures direnv to suppress those but it's a recent configuration option, so may be worth checking for an update if you see them.
+
+## Disk space
+Should you find you're running short on disk space, to delete previous versioned store data you can run `nix-collect-garbage -d`. Reentering the directory will then reinstall all the current dependencies again. It's probably a good idea to run that periodically.
+
+```shell
+direnv: export +ALLOWED_HOSTS +AR +AS...
+```