Avoid Liquid syntax errors

Author: dwijnand

_overviews/core/collections-migration-213.md

@@ -142,10 +142,8 @@ import scala.annotation.compileTimeOnly
   * `scala.collection.immutable.Seq`.  In this code base usage of unqualified `Seq` is banned: use
   * `sc.Seq` or `sci.Seq` instead.
   *
-  * {{{
   * import scala.{ collection => sc }
   * import scala.collection.{ immutable => sci }
-  * }}}
   *
   * This `Seq` trait is a dummy type to prevent the use of `Seq`.
   */
@@ -157,10 +155,8 @@ private[example] trait Seq[A1, F1[A2], A3]
   * `scala.collection.immutable.IndexedSeq`.  In this code base usage of unqualified `IndexedSeq` is
   * banned: use `sc.IndexedSeq` or `sci.IndexedSeq`.
   *
-  * {{{
   * import scala.{ collection => sc }
   * import scala.collection.{ immutable => sci }
-  * }}}
   *
   * This `IndexedSeq` trait is a dummy type to prevent the use of `IndexedSeq`.
   */