gnu: Add emacs-esxml.

* gnu/packages/emacs.scm (emacs-esxml): New variable.

gnu/packages/emacs.scm

@@ -3559,6 +3559,28 @@ (define-public emacs-epl
 @code{package.el} into a sane API.")
     (license license:gpl3+)))
 
+(define-public emacs-esxml
+  (package
+    (name "emacs-esxml")
+    (version "0.3.4")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append
+                    "https://github.com/tali713/esxml/archive/"
+                    version ".tar.gz"))
+              (sha256
+               (base32
+                "01yk4ibbln3ykrin2124hfdi53fsp9gv7j49qw93s2ls52c9zb2f"))))
+    (build-system emacs-build-system)
+    (home-page "https://github.com/tali713/esxml")
+    (synopsis "Elisp library for working with XML, ESXML and SXML")
+    (description
+     "This library provides two formats for XML code generation.  The primary
+form is esxml.  This is the form that is returned by such functions as
+@code{libxml-parse-xml-region} and it is used internally by emacs in many
+xml-related libraries.")
+    (license license:gpl3+)))
+
 (define-public emacs-queue
   (package
     (name "emacs-queue")