package-lists/emacs: Add helm-sly and sly contribs.

.package-lists/guix-manifest.scm

@@ -45,6 +45,7 @@
     "emacs-helm-org"
     "emacs-helm-org-contacts"
     "emacs-helm-pass"
+    "emacs-helm-sly"
     "emacs-helm-system-packages"
     "emacs-helpful"
     "emacs-hl-todo"
@@ -78,6 +79,9 @@
     "emacs-sly"
     "emacs-sly-asdf"
     "emacs-sly-quicklisp"
+    "emacs-sly-macrostep"
+    "emacs-sly-named-readtables"
+    ;; "emacs-sly-package-inferred" ; TODO: This package triggers an infinite recursion.
     "emacs-strace-mode"
     "emacs-suggest"
     "emacs-sx"