gnu: Add texlive-inputenx.

* gnu/packages/tex.scm (texlive-inputenx): New variable.

gnu/packages/tex.scm

@@ -2775,6 +2775,25 @@ patterns supporting a number of Cyrillic font encodings, including T2,
 UCY (Omega Unicode Cyrillic), LCY, LWN (OT2), and koi8-r.")
       (license license:lppl))))
 
+(define-public texlive-inputenx
+  (package
+    (inherit (simple-texlive-package
+              "texlive-inputenx"
+              (list "doc/latex/inputenx/"
+                    "tex/latex/inputenx/"
+                    "source/latex/inputenx/")
+              (base32
+               "0snjndrcynm4w8m9iq8gmadzhrbwvsdy4y1ak24ia0hpsicdi4aj")
+              #:trivial? #t))
+    (home-page "https://ctan.org/macros/latex/contrib/inputenx")
+    (synopsis "Enhanced input encoding handling")
+    (description
+     "This package deals with input encodings.  It provides a wider range of input
+encodings using standard mappings, than does inputenc; it also covers nearly all
+slots.  In this way, it serves as more uptodate replacement for package
+inputenc.")
+    (license license:lppl1.3+)))
+
 (define-public texlive-kpathsea
   (let ((template (simple-texlive-package
                    "texlive-kpathsea"