added c-mode config with LSP support, and added flymake to sh-mode

lisp/init-c.el

@@ -0,0 +1,20 @@
+;; *** C
+
+(use-package c-mode
+  :ensure nil ;; installed in site-lisp
+  :defer nil
+
+  :init
+  (when (fboundp 'lsp-deferred)
+    (defun lsp-c-install-save-hooks ()
+      (add-hook 'before-save-hook #'lsp-format-buffer t t)
+      (add-hook 'before-save-hook #'lsp-organize-imports t t))
+
+    (add-hook 'c-mode-hook #'lsp-deferred)
+    (add-hook 'c-mode-hook #'lsp-c-install-save-hooks)
+
+    ;; c-mode sets TAB to 'c-indent-line-or-region by default which collides with corfu.
+    (add-hook 'c-mode-hook (lambda () (define-key c-mode-map (kbd "<tab>") #'indent-for-tab-command)))))
+
+(provide 'init-c)
+;;; init-c.el ends here