Add lint.

Author: LawnGnome

app/templates/crate/delete.hbs

@@ -23,7 +23,11 @@
       <p>
         A crate can only be deleted if it is not depended upon by any other crate on crates.io. (This is a temporary
         restriction due to
-        <a href='https://github.com/rust-lang/crates.io/issues/10538' target='_blank'>#10538</a>.)
+        <a
+          href='https://github.com/rust-lang/crates.io/issues/10538'
+          target='_blank'
+          rel='noopener noreferrer'
+        >#10538</a>.)
       </p>
       <p>Additionally, a crate can only be deleted if either:</p>
       <ol local-class='first'>