exempt hbs from linkchecker

src/tools/linkchecker/main.rs

@@ -121,6 +121,12 @@ fn check(cache: &mut Cache,
     if file.extension().and_then(|s| s.to_str()) == Some("js") {
         return None;
     }
+
+    // ignore handlebars files as they use {{}} to build links, we only
+    // want to test the generated files
+    if file.extension().and_then(|s| s.to_str()) == Some("hbs") {
+        return None;
+    }
 
     // Unfortunately we're not 100% full of valid links today to we need a few
     // whitelists to get this past `make check` today.