When attempting to follow the docs on the installer, this error comes
up:
```
$ clan flash --flake git+https://git.clan.lol/clan/clan-core \
--ssh-pubkey ~/.ssh/id_ed25519.pub \
--keymap us \
--language en_US.utf-8 \
--dry-run flash-installer
ERROR: Language 'en_US.utf-8' is not a valid language. Run 'clan flash --list-languages' to see a list of possible languages.
```
I only decided to clean up the docs, but I'm also okay with just
downcasing the locales in `list_possible_languages()`.
- add index pages for each reference documentation category
- move concepts pages into the reference hierarchy
- render clanModules overview page in the style of the CLI overview
This reverts commit 18b64f2d0b.
The old configuration cannot be updated like this:
eve] error:
[eve] … while calling the 'head' builtin
[eve] at /nix/store/5b0hl2dnvr1sawqlkwmsnaiyqz00d34h-source/lib/attrsets.nix:1575:11:
[eve] 1574| || pred here (elemAt values 1) (head values) then
[eve] 1575| head values
[eve] | ^
[eve] 1576| else
[eve]
[eve] … while evaluating the attribute 'value'
[eve] at /nix/store/5b0hl2dnvr1sawqlkwmsnaiyqz00d34h-source/lib/modules.nix:809:9:
[eve] 808| in warnDeprecation opt //
[eve] 809| { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
[eve] | ^
[eve] 810| inherit (res.defsFinal') highestPrio;
[eve]
[eve] … while evaluating the option `system.build.toplevel':
[eve]
[eve] … while evaluating definitions from `/nix/store/5b0hl2dnvr1sawqlkwmsnaiyqz00d34h-source/nixos/modules/system/activation/top-level.nix':
[eve]
[eve] … while evaluating the option `assertions':
[eve]
[eve] … while evaluating definitions from `/nix/store/5b0hl2dnvr1sawqlkwmsnaiyqz00d34h-source/nixos/modules/system/boot/systemd.nix':
[eve]
[eve] … while evaluating the option `systemd.services':
[eve]
[eve] … while evaluating definitions from `/nix/store/kpzcdgndym0qm1w490mjvk9c2qmz03h5-source/nixosModules/clanCore/zerotier':
[eve]
[eve] … while evaluating the option `clan.core.networking.zerotier.networkId':
[eve]
[eve] (stack trace truncated; use '--show-trace' to show the full, detailed trace)
[eve]
[eve] error: A definition for option `clan.core.networking.zerotier.networkId' is not of type `null or string'. Definition values:
[eve] - In `/nix/store/kpzcdgndym0qm1w490mjvk9c2qmz03h5-source/nixosModules/clanCore/networking.nix':
[eve] {
[eve] _type = "override";
[eve] content = "267efd4a15b69623";
[eve] priorit
Injecting nixos configuration and potentially overriding settings a user
made and can cause surprises.
In most cases, users want to just make these option part of their NixOS
configuration and by having the rest in the command line
we make it more explicit what other configuration is being applied.
