Rethink smartparens config #181

+ Parts of my smartparens config that were personal preference have been
  moved to my private module.
+ The css-mode config was redundant and was removed
+ Moved lang-specific config to their respective modules
+ Markdown config was redundant with native electric support, and thus
  removed.

modules/lang/markdown/config.el

@@ -20,14 +20,7 @@
     (setq line-spacing 2
           fill-column 80))
 
-  (sp-local-pair
-   '(markdown-mode gfm-mode)
-   "\`\`\`" "\`\`\`" :post-handlers '(("||\n" "RET")))
-
-  (map! (:map gfm-mode-map
-          "`" #'self-insert-command)
-
-        (:map markdown-mode-map
+  (map! (:map markdown-mode-map
           [remap find-file-at-point] #'markdown-follow-thing-at-point
           "M-*"      #'markdown-insert-list-item
           "M-b"      #'markdown-insert-bold