Pass lang to taxonomy list template

Closes #963

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## 0.10.2 (unreleased)
 
 - Fix link checker not looking for anchor with capital id/name
+- Pass missing `lang` template parameter to taxonomy list template
 
 ## 0.10.1 (2020-03-12)
 

components/library/src/taxonomies/mod.rs

@@ -169,6 +169,7 @@ impl Taxonomy {
         let terms: Vec<SerializedTaxonomyItem> =
             self.items.iter().map(|i| SerializedTaxonomyItem::from_item(i, library)).collect();
         context.insert("terms", &terms);
+        context.insert("lang", &self.kind.lang);
         context.insert("taxonomy", &self.kind);
         context.insert("current_url", &config.make_permalink(&self.kind.name));
         context.insert("current_path", &self.kind.name);