emacs-org-roam: Add new phase after unpack.

* gnu/packages/emacs-xyz.scm (emacs-org-roam)[arguments]<phases>:
After the unpack phase add a move-source-files phase to include
the org-roam extensions to the package.

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

gnu/packages/emacs-xyz.scm

@@ -28245,6 +28245,15 @@ (define-public emacs-org-roam
     (arguments
      `(#:phases
        (modify-phases %standard-phases
+         ;; Move the extensions source files to the top level, which is included in
+         ;; the EMACSLOADPATH.
+         (add-after 'unpack 'move-source-files
+           (lambda _
+             (let ((el-files (find-files "./extensions" ".*\\.el$")))
+               (for-each (lambda (f)
+                           (rename-file f (basename f)))
+                         el-files))
+             #t))
          (add-after 'install 'install-image
            (lambda* (#:key outputs #:allow-other-keys)
              (let ((out (assoc-ref outputs "out")))