chore: put backend host in an environment variable

src/pages/category/[category]/[slug]/index.astro

@@ -15,6 +15,8 @@ export async function getStaticPaths() {
     props: { entry },
   }));
 }
+
+const backendHost = import.meta.env.PUBLIC_BACKEND_HOST;
 ---
 
 <style>
@@ -34,13 +36,13 @@ export async function getStaticPaths() {
   <Post post={entry} componentType="full" />
 
   <form
-    hx-post="http://localhost:8000/blog/api/forms/emoji/post"
+    hx-post=`${backendHost}/blog/api/forms/emoji/post`
     hx-target="#reaction-buttons"
   >
     <input type="hidden" name="postId" value=`${entry.id}` />
     <div
       id="reaction-buttons"
-      hx-get=`http://localhost:8000/blog/api/forms/emoji?postId=${entry.id}`
+      hx-get=`${backendHost}/blog/api/forms/emoji?postId=${entry.id}`
       hx-trigger="load"
       hx-swap="innerHTML"
     >