update emacs config to 21th century

conf-lisp/dumpjump.el

@@ -0,0 +1,24 @@
+;; *** Dumpjump
+;; https://github.com/jacktasia/dumb-jump/raw/master/dumb-jump.el
+(use-package dumb-jump
+             :config
+
+             (add-hook 'xref-backend-functions #'dumb-jump-xref-activate)
+             (setq xref-show-definitions-function #'xref-show-definitions-completing-read)
+
+             (setq dumb-jump-quiet t)
+
+             (when (fboundp 'defhydra)
+               (defhydra hydra-dumb-jump (:color blue :columns 3)
+                 "Dumb Jump"
+                 ("j" dumb-jump-go "Go")
+                 ("o" dumb-jump-go-other-window "Other window")
+                 ("e" dumb-jump-go-prefer-external "Go external")
+                 ("x" dumb-jump-go-prefer-external-other-window "Go external other window")
+                 ("i" dumb-jump-go-prompt "Prompt")
+                 ("l" dumb-jump-quick-look "Quick look")
+                 ("b" dumb-jump-back "Back"))
+
+               (global-set-key (kbd "C-x j") 'hydra-dumb-jump/body))
+             (global-set-key (kbd "C-c j") 'dumb-jump-go)
+             (global-set-key (kbd "C-c b") 'dumb-jump-back))