vendor ibm-plex

i don't like how we're doing this lol. setting the IBM_PLEX_WEB env var feels wrong.

doerg/package.nix

@@ -1,15 +1,34 @@
 { mkCljBin
 , callPackage
 , doerg-parser
+, ibm-plex-web
+, fake-git
 }:
 
-mkCljBin {
+let
+  # mkCljBin sans fake-git.
+  mkCljBin' = args: (mkCljBin args).overrideAttrs (final: prev: {
+    nativeBuildInputs =
+      builtins.filter
+	# A possibly-sketchy predicate, lol.
+	(x: x != fake-git)
+	prev.nativeBuildInputs;
+  });
+
+  plex = ibm-plex-web.override {
+    families = [ "math" "serif" "sans-kr" ];
+  };
+in mkCljBin' {
   name = "net.deertopia/doerg";
   version = "0.1.0";
   projectSrc = ./.;
   lockfile = ../deps-lock.json;
   main-ns = "net.deertopia.doerg.main";
+  nativeBuildInputs = [
+    plex
+  ];
   buildInputs = [
     doerg-parser
+    plex
   ];
 }