docs: add og-image example

exampleSite/content/blog/og-image/index.md

@@ -0,0 +1,44 @@
++++
+title = "og-image"
+date = "2024-05-08"
+images = ["og-image/kateryna-ivanova-etgAEeMw2wc-unsplash.jpg"]
+# OR:
+# images = ["https://example.com/foo.png"]
++++
+
+> <https://github.com/gohugoio/hugo/blob/c46d603a027a715db604d39f7a2e68a157ef0001/docs/_vendor/github.com/gohugoio/gohugoioTheme/layouts/partials/opengraph/opengraph.html>
+
+```plaintext {hl_lines=["8-10"]}
+.
+├── _index.md
+└── blog
+    ├── _index.md
+    ├── emoji-support.md
+    ├── markdown-syntax.md
+    ├── math-typesetting.md
+    ├── og-image
+    │   ├── index.md
+    │   └── kateryna-ivanova-etgAEeMw2wc-unsplash.jpg
+    ├── placeholder-text.md
+    └── rich-content.md
+```
+
+Page params:
+
+```toml {hl_lines=["3-4"]}
+title = "og-image"
+date = "2024-05-08"
+images = ["/og-image/kateryna-ivanova-etgAEeMw2wc-unsplash.jpg"]
+# OR:
+# images = ["https://example.com/foo.png"]
+```
+
+Output HTML:
+
+```html
+...
+
+<meta property="og:image" content="http://localhost:1313/og-image/kateryna-ivanova-etgAEeMw2wc-unsplash.jpg">
+
+...
+```