seo: add meta tags

Author: avivace

list/README.md

@@ -1,5 +1,13 @@
 ---
 sidebar: false
+head:
+  - - meta
+    - name: og:title
+      content: gbdev.io homepage
+  - - meta
+    - name: og:description
+      content: Home of the Game Boy and Game Boy Advance homebrew development scene.
+We are working on (open) development tools, documentation and digital preservation.
 ---
 
 <div id='outer'>

list/chat.md

@@ -1,5 +1,12 @@
 ---
 sidebar: false
+head:
+  - - meta
+    - name: og:title
+      content: gbdev chat channels
+  - - meta
+    - name: og:description
+      content: Join gbdev.io community channels
 ---
 
 # Community chat channels

list/gbcompo21.md

@@ -1,3 +1,13 @@
+---
+head:
+  - - meta
+    - name: og:title
+      content: GB Compo 2021
+  - - meta
+    - name: og:description
+      content: An OG game competition! Create original games, demos, homebrews tools and music for the original Game Boy / Game Boy Color and compete for glory (and a lot of prizes)!
+---
+
 # Game Boy Competition 2021
 
 <p align="center">

list/list.md

@@ -1,6 +1,13 @@
 ---
-title: Awesome list
+title: Resources
 lang: en-US
+head:
+  - - meta
+    - name: og:title
+      content: Game Boy dev resources
+  - - meta
+    - name: og:description
+      content: A curated list of awesome Development resources, tools, docs, related projects and homebrews.
 ---
 
 <br>