Add missing SQL file link for 2021 accessibility Heading hierarchy score (#3047)

* Add missing SQL file link for 2021 accessibility Heading hierarchy score

* Add lighthouse_a11y_audits.sql SQL file to Japanese translation

Author: thibaudcolas

src/content/en/2021/accessibility.md

@@ -301,7 +301,7 @@ Headings make it easier for screen readers to properly navigate a page by supply
   content="58%",
   classes="big-number",
   sheets_gid="461215072",
-  sql_file="???"
+  sql_file="lighthouse_a11y_audits.sql"
 )
 }}
 

src/content/ja/2021/accessibility.md

@@ -301,7 +301,7 @@ HTML5導入以前は、これを実現するためにARIAのランドマーク
   content="58%",
   classes="big-number",
   sheets_gid="461215072",
-  sql_file="???"
+  sql_file="lighthouse_a11y_audits.sql"
 )
 }}