treewide: Fix all Nix ASTs in all markdown files

This allows for correct highlighting and maybe future automatic
formatting. The AST was verified to work with nixfmt only.

doc/hooks/breakpoint.section.md

@@ -3,7 +3,9 @@
 This hook will make a build pause instead of stopping when a failure happens. It prevents nix from cleaning up the build environment immediately and allows the user to attach to a build environment using the `cntr` command. Upon build error it will print instructions on how to use `cntr`, which can be used to enter the environment for debugging. Installing cntr and running the command will provide shell access to the build sandbox of failed build. At `/var/lib/cntr` the sandboxed filesystem is mounted. All commands and files of the system are still accessible within the shell. To execute commands from the sandbox use the cntr exec subcommand. `cntr` is only supported on Linux-based platforms. To use it first add `cntr` to your `environment.systemPackages` on NixOS or alternatively to the root user on non-NixOS systems. Then in the package that is supposed to be inspected, add `breakpointHook` to `nativeBuildInputs`.
 
 ```nix
-nativeBuildInputs = [ breakpointHook ];
+{
+  nativeBuildInputs = [ breakpointHook ];
+}
 ```
 
 When a build failure happens there will be an instruction printed that shows how to attach with `cntr` to the build sandbox.

doc/hooks/installShellFiles.section.md

@@ -7,19 +7,21 @@ The `installManPage` function takes one or more paths to manpages to install. Th
 The `installShellCompletion` function takes one or more paths to shell completion files. By default it will autodetect the shell type from the completion file extension, but you may also specify it by passing one of `--bash`, `--fish`, or `--zsh`. These flags apply to all paths listed after them (up until another shell flag is given). Each path may also have a custom installation name provided by providing a flag `--name NAME` before the path. If this flag is not provided, zsh completions will be renamed automatically such that `foobar.zsh` becomes `_foobar`. A root name may be provided for all paths using the flag `--cmd NAME`; this synthesizes the appropriate name depending on the shell (e.g. `--cmd foo` will synthesize the name `foo.bash` for bash and `_foo` for zsh). The path may also be a fifo or named fd (such as produced by `<(cmd)`), in which case the shell and name must be provided.
 
 ```nix
-nativeBuildInputs = [ installShellFiles ];
-postInstall = ''
-  installManPage doc/foobar.1 doc/barfoo.3
-  # explicit behavior
-  installShellCompletion --bash --name foobar.bash share/completions.bash
-  installShellCompletion --fish --name foobar.fish share/completions.fish
-  installShellCompletion --zsh --name _foobar share/completions.zsh
-  # implicit behavior
-  installShellCompletion share/completions/foobar.{bash,fish,zsh}
-  # using named fd
-  installShellCompletion --cmd foobar \
-    --bash <($out/bin/foobar --bash-completion) \
-    --fish <($out/bin/foobar --fish-completion) \
-    --zsh <($out/bin/foobar --zsh-completion)
-'';
+{
+  nativeBuildInputs = [ installShellFiles ];
+  postInstall = ''
+    installManPage doc/foobar.1 doc/barfoo.3
+    # explicit behavior
+    installShellCompletion --bash --name foobar.bash share/completions.bash
+    installShellCompletion --fish --name foobar.fish share/completions.fish
+    installShellCompletion --zsh --name _foobar share/completions.zsh
+    # implicit behavior
+    installShellCompletion share/completions/foobar.{bash,fish,zsh}
+    # using named fd
+    installShellCompletion --cmd foobar \
+      --bash <($out/bin/foobar --bash-completion) \
+      --fish <($out/bin/foobar --fish-completion) \
+      --zsh <($out/bin/foobar --zsh-completion)
+  '';
+}
 ```

doc/hooks/mpi-check-hook.section.md

@@ -12,13 +12,14 @@ Example:
 
 ```nix
   { mpiCheckPhaseHook, mpi, ... }:
+  {
+    # ...
 
-  ...
-
-  nativeCheckInputs = [
-    openssh
-    mpiCheckPhaseHook
-  ];
+    nativeCheckInputs = [
+      openssh
+      mpiCheckPhaseHook
+    ];
+  }
 ```