Activate flyspell-mode in specific modes

yaml-mode is derived from text-mode, rather than prog or conf-mode. This
may be true for other major modes, so we must be more judicious about
where we activate flyspell-mode.

modules/checkers/spell/config.el

@@ -48,9 +48,18 @@
         ;; messages for every word when checking the entire buffer
         flyspell-issue-message-flag nil)
 
-  (add-hook 'text-mode-hook #'flyspell-mode)
+  (add-hook! '(org-mode-hook
+               markdown-mode-hook
+               TeX-mode-hook
+               rst-mode-hook
+               mu4e-compose-mode-hook
+               message-mode-hook)
+             #'flyspell-mode)
+
   (when (featurep! +everywhere)
-    (add-hook! '(conf-mode-hook prog-mode-hook)
+    (add-hook! '(yaml-mode-hook
+                 conf-mode-hook
+                 prog-mode-hook)
                #'flyspell-prog-mode))
 
   (add-hook! 'flyspell-mode-hook

modules/email/mu4e/config.el

@@ -91,9 +91,6 @@
   (defadvice! +mu4e--refresh-current-view-a (&rest _)
     :after #'mu4e-mark-execute-all (mu4e-headers-rerun-search))
 
-  (when (featurep! :checkers spell)
-    (add-hook 'mu4e-compose-mode-hook #'flyspell-mode))
-
   ;; Wrap text in messages
   (setq-hook! 'mu4e-view-mode-hook truncate-lines nil)