Add cdlatex support in latex: +cdlatex

cdlatex has 4 main functionalities:
+ Math and environments snippets: I've disabled these in favor of
  yasnippet when using :editor snippets by just unbinding the TAB in
  cdlatex's keymap
+ Auto insertion of closing delimiters: disabled in favor of smartparens
+ Fast insertion for some macros: `a becomes \alpha. Kept as-is
+ Fast accent insertion: a'~ becomes \tilde{a}. Kept as-is

I also updated the docs, and added a section explaining how to re-enable
cdlatex's snippets despite having yasnippet.

modules/lang/latex/config.el

@@ -119,6 +119,30 @@ If no viewers are found, `latex-preview-pane' is used.")
                 (lambda () (* (/ 10.0 (preview-document-pt)) preview-scale))))
 
 
+(use-package! cdlatex
+  :defer t
+  :when (featurep! +cdlatex)
+  :hook (LaTeX-mode . cdlatex-mode)
+  :config
+  ;; Disabling keys that have overlapping functionality with other parts of Doom
+  ;; smartparens takes care of inserting closing delimiters
+  (define-key cdlatex-mode-map  "$" nil)
+  (define-key cdlatex-mode-map  "(" nil)
+  (define-key cdlatex-mode-map  "{" nil)
+  (define-key cdlatex-mode-map  "[" nil)
+  (define-key cdlatex-mode-map  "|" nil)
+  (define-key cdlatex-mode-map  "<" nil)
+  ;; TAB is used for cdlatex's snippets and navigation. But have yasnippet for that.
+  (when (featurep! :editor snippets)
+    (define-key cdlatex-mode-map  "\t" nil))
+
+  ;; AUCTeX takes care of auto-inserting {} on _^ if you want, with `TeX-electric-sub-and-superscript'
+  (define-key cdlatex-mode-map  "^" nil)
+  (define-key cdlatex-mode-map  "_" nil)
+  ;; AUCTeX already provides this with `LaTeX-insert-item'
+  (define-key cdlatex-mode-map  [(control return)] nil))
+
+
 ;; Nicely indent lines that have wrapped when visual line mode is activated
 (use-package! adaptive-wrap
   :hook (LaTeX-mode . adaptive-wrap-prefix-mode)