Disable Smartypants Markdown plugin

SmartyPants is a Markdown plugin that converts:

- Straight and backtick-style quotes into “curly” quote HTML entities
- Dashes (“--” and “---”) into en- and em-dash entities
- Three consecutive dots (“...”) into an ellipsis entity

The result of this is inconsistent typography. Markdown and MDX pages
are converted, whereas `.astro` pages (like `about.astro`) are not.
This commit will disable SmartyPants.

https://daringfireball.net/projects/smartypants/
https://docs.astro.build/en/reference/configuration-reference/

astro.config.mjs

@@ -8,6 +8,7 @@ export default defineConfig({
     shikiConfig: {
       theme: "dracula",
     },
+    smartypants: false,
   },
   site: "https://www.bws.bio",
 })