use markcode to doc for all .nix file

.gitignore

@@ -2,3 +2,4 @@ result*
 .direnv
 book/
 SUMMARY.md
+*.nix.md

Makefile

@@ -1,6 +1,11 @@
 all: SUMMARY.md
 	mdbook build
 
+NIXs = $(shell find . -name "*.nix" -not -path "./book*")
+NIX_MDs = $(addsuffix .md,${NIXs})
+%.md: %
+	markcode $< > $@
+
 .PHONY: SUMMARY.md
-SUMMARY.md: .genSUMMARY.sh
+SUMMARY.md: .genSUMMARY.sh ${NIX_MDs}
 	./$< > $@

shell.nix

@@ -1,9 +1,18 @@
 let
   name = "nix_config";
   pkgs = import <nixpkgs> {};
+  markcode = pkgs.callPackage (
+    pkgs.fetchFromGitHub {
+      owner = "xieby1";
+      repo = "markcode";
+      rev = "aab7cdedae2a90fd1dea56a81fdf85689ef9b537";
+      hash = "sha256-HCmtCnk3Q/Bng7QZzMm5C7nrKKNyz43yWLdv/CSuFyM=";
+    }
+  ) {};
 in pkgs.mkShell {
   inherit name;
   buildInputs = with pkgs; [
     mdbook
+    markcode
   ];
 }