Reduce post slug max length

Author: PaulAdamDavis

packages/mg-json/lib/to-ghost-json/validate.js

@@ -12,7 +12,7 @@ export default async (json) => {
         // String length data from https://github.com/TryGhost/Ghost/blob/main/ghost/core/core/server/data/schema/schema.js
         let properties = {
             title: 255,
-            slug: 191,
+            slug: 185,
             custom_excerpt: 300,
             og_title: 300,
             og_description: 500,

packages/mg-wp-xml/lib/process.js

@@ -214,7 +214,7 @@ const processPost = async ($post, users, options) => {
     };
 
     if (post.data.slug.trim().length === 0) {
-        post.data.slug = slugify(post.data.title).substring(0, 191);
+        post.data.slug = slugify(post.data.title).substring(0, 185);
     }
 
     post.data.html = await preProcessContent({