gnu: Add texlive-textcase.

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

gnu/packages/tex.scm

@@ -5495,6 +5495,33 @@ other programs in the distribution offer online interactive use (with
 hypertext linkages in some cases).")
     (license license:gpl3+)))
 
+(define-public texlive-textcase
+  (package
+    (inherit (simple-texlive-package
+              "texlive-textcase"
+              (list "doc/latex/textcase/"
+                    "tex/latex/textcase/"
+                    "source/latex/textcase/")
+              (base32
+               "185fibd41wd0v51gnai29ygi32snkk00p00110kcnk1bcnmpiw82")
+              #:trivial? #t))
+    (home-page "https://ctan.org/macros/latex/contrib/textcase")
+    (synopsis "Case conversion ignoring mathematics, etc")
+    (description
+     "The textcase package offers commands @code{\\MakeTextUppercase} and
+@code{\\MakeTextLowercase} are similar to the standard @code{\\MakeUppercase}
+and @code{\\MakeLowercase}, but they do not change the case of any sections of
+mathematics, or the arguments of @code{\\cite}, @code{\\label} and
+@code{\\ref} commands within the argument.  A further command
+@code{\\NoCaseChange} does nothing but suppress case change within its
+argument, so to force uppercase of a section including an environment, one
+might say:
+
+@example
+\\MakeTextUppercase{...\\NoCaseChange{\\begin{foo}} ...\\NoCaseChange{\\end{foo}}...}
+@end example\n")
+    (license license:lppl)))
+
 (define-public texlive-latex-upquote
   (package
     (name "texlive-latex-upquote")