Fix link from container-attrs to variant-attrs

Author: dtolnay

_src/container-attrs.md

@@ -80,10 +80,9 @@
 
   Identical to [`variant_identifier`](#variant_identifier), but also allows for
   the last variant to be a newtype variant, which will be used if none of the
-  other variants match (similar to
-  [`#[serde(other)]`](../variant-attrs.html#other)). Like `variant_identifier`,
-  this forces the enum to always be represented as a string, regardless of the
-  underlying data format's representation of enums.
+  other variants match (similar to [`#[serde(other)]`](variant-attrs.md#other)).
+  Like `variant_identifier`, this forces the enum to always be represented as a
+  string, regardless of the underlying data format's representation of enums.
 
 - ##### `#[serde(bound = "T: MyTrait")]` {#bound}