Properly fix ispell

I didn't want to have to deal with ispell's refusal to work with
anything but a plaintext word list, but it seems like there's no other option.

config.org

@@ -2091,6 +2091,44 @@ I like having ophints for vim editing so that I don't get lost when making large
                      '(evil-goggles-change-face :inherit evil-goggles-delete-face)))
 #+end_src
 
+** Spell Checking
+
+#+call: confpkg("Pkg: ispell")
+
+Doom Emacs sets up spell-checking with ~ispell~ (Emacs-internal tool) and =aspell= (external tool) for us, which is nice. We just need to set which dictionary to use:
+
+#+begin_src emacs-lisp
+(after! ispell
+  (setq ispell-dictionary "en_US"))
+#+end_src
+
+We also need to generate a plain-text dictionary for some ~ispell~ functionality, which is annoying, but I haven't figured out a way around it. I could use my automated nix-build system for this, but I want to have access to my =aspell= config file, so it's easier to just put it in the usual location.
+
+#+begin_src emacs-lisp
+(defvar ~/plaintext-dict (expand-file-name "ispell/dict.plain" doom-data-dir)
+  "File location of a plaintext wordlist for spellchecking.")
+
+(unless (file-readable-p ~/plaintext-dict)
+  (shell-command-to-string
+   (concat
+    "aspell -l en_US dump master > " ~/plaintext-dict ";"
+    "aspell -d en-computers.rws dump master >> " ~/plaintext-dict ";"
+    "aspell -d en_US-science.rws dump master >> " ~/plaintext-dict ";")))
+
+(after! ispell
+  (setq ispell-alternate-dictionary ~/plaintext-dict))
+#+end_src
+
+Now that we have this word list, we can also plug it into ~cape-dict~ and get proper spelling completion!
+
+#+begin_src emacs-lisp
+(after! cape
+  (setq cape-dict-file ~/plaintext-dict))
+
+(add-hook! text-mode
+  (add-hook! 'completion-at-point-functions :local :depth 40 #'cape-dict))
+#+end_src
+
 ** Snippets
 
 #+call: confpkg("Pkg: yasnippet")