Interwiki: Remove the description field

I already see people not using it

interwiki/view_interwiki.html

@@ -13,9 +13,6 @@
 						<dt>Aliases</dt>
                         {{range .Aliases}}<dd>{{.}}</dd>{{end}}
 
-						<dt>Description</dt>
-						<dd>{{.Description}}</dd>
-
 						<dt>Engine</dt>
 						<dd>{{.Engine}}</dd>
 

interwiki/wiki.go

@@ -42,9 +42,6 @@ type Wiki struct {
 
 	ImgSrcFormat string `json:"img_src_format"`
 
-	// Description is a plain-text description of the wiki. Can be empty.
-	Description string `json:"description,omitempty"`
-
 	// Engine is the engine of the wiki. Invalid values will result in a start-up error.
 	Engine WikiEngine `json:"engine"`
 }