treewide: fix typos in comments (#413240)

  /**

    Get the first of the `outputs` provided by the package, or the default.

    This function is alligned with `_overrideFirst()` from the `multiple-outputs.sh` setup hook.

    This function is aligned with `_overrideFirst()` from the `multiple-outputs.sh` setup hook.

    Like `getOutput`, the function is idempotent.

    # Inputs

      extensions = composeManyExtensions [ overlayA overlayB ];

      # Caluculate the fixed point of all composed overlays.

      # Calculate the fixed point of all composed overlays.

      fixedpoint = lib.fix (lib.extends extensions original );

    in fixedpoint

    ```nix

    myType = mkOptionType {

      name = "myType";

      merge = mergeDefaultOption; # <- This line is redundant. It is the default aready.

      merge = mergeDefaultOption; # <- This line is redundant. It is the default already.

    };

    ```

    args@{

      message,

      # WARNING: the default merge function assumes that the definition is a valid (option) value. You MUST pass a merge function if the return value needs to be

      #   - type checked beyond what .check does (which should be very litte; only on the value head; not attribute values, etc)

      #   - type checked beyond what .check does (which should be very little; only on the value head; not attribute values, etc)

      #   - if you want attribute values to be checked, or list items

      #   - if you want coercedTo-like behavior to work

      merge ? loc: defs: (head defs).value,

    if pos == null then "" else " at ${pos.file}:${toString pos.line}:${toString pos.column}";

  # Internal functor to help for migrating functor.wrapped to functor.payload.elemType

  # Note that individual attributes can be overriden if needed.

  # Note that individual attributes can be overridden if needed.

  elemTypeFunctor =

    name:

    { elemType, ... }@payload:

  Documentation rendered as AsciiDoc. This is useful for e.g. man pages.

  > Note: NixOS itself uses this ouput to to build the configuration.nix man page"

  > Note: NixOS itself uses this output to to build the configuration.nix man page"

  ## optionsNix

  let

    # Evaluate a NixOS configuration

    eval = import (pkgs.path + "/nixos/lib/eval-config.nix") {

      # Overriden explicitly here, this would include all modules from NixOS otherwise.

      # Overridden explicitly here, this would include all modules from NixOS otherwise.

      # See: docs of eval-config.nix for more details

      baseModules = [];

      modules = [