add: article about Setting Up SSH Authentication for GitHub

Author: szuryuu

src/fixtures/fixtures/page-with-frontmatter-error.md

@@ -1,7 +1,6 @@
 ---
-title: "This is an article"
-intro: "I've got broken frontmatter"
+title: This is an article
+intro: 'I've got broken frontmatter'
 versions:
-  free-pro-team: "*"
-type: "article"
+  free-pro-team: '*'
 ---

src/frame/tests/site-tree.js

@@ -69,7 +69,7 @@ function validate(currentPage) {
 
     expect(isValid, errors).toBe(true)
 
-    // Run recursively until we run out of child pages to validate
+    // Run recursively until we run out of child pages
     validate(childPage)
   })
 }