init.el: Update emacs config

Allow automatic updation of packages. We do not have LSP
integration working yet.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>

init.el

@@ -79,6 +79,13 @@
              :config
              (evil-mode 1))
 
+(use-package auto-package-update
+             :ensure t
+             :config
+             (setq auto-package-update-delete-old-versions t
+                   auto-package-update-interval 4)
+             (auto-package-update-maybe))
+
 (use-package evil-escape
              :ensure t
              :init
@@ -184,16 +191,25 @@
              (haskell-stylish-on-save t)
              (haskell-process-suggest-remove-import-lines t))
 (use-package lsp-mode
-             :defer t
              :ensure t
              :commands lsp)
 (use-package lsp-ui
-             :requires lsp-mode
+             :ensure t
+             :after lsp-mode
              :hook
-             ((lsp-mode-hook . lsp-ui-mode)
-              (haskell-mode-hook . flycheck-mode)))
+             ((lsp-mode . lsp-ui-mode)
+              (lsp-ui-mode . lsp-ui-peek-mode)
+              (haskell-mode . lsp-haskell-enable)
+              (haskell-mode . flycheck-mode)
+              (rust-mode . lsp-rust-enable)
+              (rust-mode . flycheck-mode)
+              (python-mode . lsp-python-enable)
+              (python-mode . flycheck-mode)
+              ))
 (use-package company-lsp
-             :commands company-lsp)
+             :commands company-lsp
+             :config
+             (push 'company-lsp company-backends))
 
 (use-package lsp-haskell
              :defer t