added renderer selection (py-gfm as alternative)

examples.md

@@ -11,6 +11,7 @@ Root directory manifest (`.wp-materialize.json`):
   "categories": { "content": ["Systems", "Infrastructure"], "inherit": true },
   "tags": { "content": ["automation", "wordpress"], "inherit": true },
   "author": { "content": ["editorial"], "inherit": true },
+  "renderer": "py-gfm",
   "subdirectories": { "content": ["design", "notes"], "inherit": true },
   "files": {
     "post.md": {
@@ -20,6 +21,7 @@ Root directory manifest (`.wp-materialize.json`):
     },
     "essay.md": {
       "use_heading_as_title": { "level": 1, "strict": true },
+      "renderer": "default",
       "created_on": "2025-01-10 09:30",
       "last_modified": "2025-02-14 16:45"
     }
@@ -48,6 +50,7 @@ Subdirectory manifest (`design/.wp-materialize.json`):
 {
   "wordpress_root": "/var/www/wordpress",
   "repo_storage_dir": "/home/user/wp-materialize-repos",
+  "renderer": "default",
   "git_repositories": [],
   "directories": [
     {
@@ -65,6 +68,7 @@ Subdirectory manifest (`design/.wp-materialize.json`):
 {
   "wordpress_root": "/var/www/wordpress",
   "repo_storage_dir": "/home/user/wp-materialize-repos",
+  "renderer": "default",
   "git_repositories": [
     {
       "name": "content-repo",
@@ -95,6 +99,7 @@ Subdirectory manifest (`design/.wp-materialize.json`):
 {
   "wordpress_root": "/var/www/wordpress",
   "repo_storage_dir": "/home/user/wp-materialize-repos",
+  "renderer": "default",
   "git_repositories": [
     {
       "name": "content-repo",