Make Github's Nix highlighter happy

The highlighter expects that all code blocks are valid expressions (to
some degree) and highlights mismatches in dark red, which is not
particularly pleasant for the reader.

This introduces a "fake" attribute set in the `inherit` section to
please the highlighter.

nix/nix-1p/README.md

@@ -29,6 +29,9 @@ important is missing.
     - [`pkgs` itself](#pkgs-itself)
 - [Derivations](#derivations)
 - [Nix Idioms](#nix-idioms)
+    - [File lambdas](#file-lambdas)
+    - [`callPackage`](#callpackage)
+    - [Overrides / Overlays](#overrides--overlays)
 
 <!-- markdown-toc end -->
 
@@ -253,9 +256,10 @@ This is often convenient, especially because inherit supports multiple variables
 at the same time as well as "inheritance" from other attribute sets:
 
 ```nix
-inherit name age; # equivalent to `name = name; age = age;`
-
-inherit (otherAttrs) email; # equivalent to `email = otherAttrs.email`;
+{
+  inherit name age; # equivalent to `name = name; age = age;`
+  inherit (otherAttrs) email; # equivalent to `email = otherAttrs.email`;
+}
 ```
 
 ## `with` statements