gnu: Add elixir-ex-doc.

* gnu/packages/elixir-markup.scm (elixir-ex-doc): New variable.

Change-Id: I6d38495063e3942423c0fa1d3dfbf1819324a0c4
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/elixir-markup.scm

@@ -89,6 +89,32 @@ item A @code{String.Chars} implementation to convert them to text
     (home-page "https://hexdocs.pm/easyhtml/")
     (license license:asl2.0)))
 
+(define-public elixir-ex-doc
+  (package
+    (name "elixir-ex-doc")
+    (version "0.38.4")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (hexpm-uri "ex_doc" version))
+       (sha256
+        (base32 "1ck5y70zkppyswpagvla4zh19cryc4slw5c04lf930wa81327dpp"))))
+    (build-system mix-build-system)
+    (arguments
+     ;; FIXME: tests depend on lazy_html which is not yet packaged.
+     (list #:tests? #f))
+    (native-inputs
+     (list elixir-easyhtml
+           elixir-jason
+           elixir-floki))
+    (propagated-inputs
+     (list elixir-earmark-parser elixir-makeup-c elixir-makeup-elixir
+           elixir-makeup-erlang elixir-makeup-html))
+    (synopsis "Documentation generation tool for Elixir")
+    (description "@code{ExDoc} is a documentation generation tool for Elixir.")
+    (home-page "https://hexdocs.pm/ex_doc/")
+    (license license:asl2.0)))
+
 (define-public elixir-floki
   (package
     (name "elixir-floki")