gnu: Add emacs-popon.

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

Signed-off-by: Nicolas Goaziou <mail@nicolasgoaziou.fr>

gnu/packages/emacs-xyz.scm

@@ -31407,6 +31407,33 @@ (define-public emacs-osm
 parallel fetching of tiles with cURL, and more.")
     (license license:gpl3+)))
 
+(define-public emacs-popon
+  ;; Upstream does not tag releases.  The commit below matches the version
+  ;; bump.
+  (let ((commit "d16cb747d356eab3f1bc4061ecee473732f7b8bb"))
+    (package
+      (name "emacs-popon")
+      (version "0.4")
+      (source
+       (origin
+         (method git-fetch)
+         (uri
+          (git-reference
+           (url "https://codeberg.org/akib/emacs-popon")
+           (commit commit)))
+         (file-name (git-file-name name version))
+         (sha256
+          (base32 "1i5rp0gvcdqakzaznsh0lqzvlq5kif9q2grq4l80gl75dmqdpym7"))))
+      (build-system emacs-build-system)
+      (home-page "https://codeberg.org/akib/emacs-popon/")
+      (synopsis "Pop floating text on a window")
+      (description
+       "@code{emacs-popon} allows you to pop text on a window, what we call
+a popon.  Popons are window-local and sticky, they don't move while
+scrolling, and they even don't go away when switching buffer, but you
+can bind a popon to a specific buffer to only show on that buffer.")
+      (license license:gpl3+))))
+
 (define-public emacs-bitbake-modes
   (package
    (name "emacs-bitbake-modes")