Update v.edit.html (#223)

Say tool=zbulk. Else users will Google how to download some software called zbulk.

vector/v.edit/v.edit.html

@@ -5,7 +5,7 @@ via command line interface.
 
 <p><em>v.edit</em> supports only "simple" vector features: points,
 centroids, lines and boundaries. Currently, only 2D vector features
-(except of tool <b>zbulk</b>) are supported.
+(except of <b>tool=zbulk</b>) are supported.
 
 <p>Provides editing features' geometry. Attribute data connected to the
 vector map are not modified at all.
@@ -414,7 +414,7 @@ v.edit map=roads tool=select bbox=598260,4919730,605100,4926240 query=length thr
 <h3>Fix height of contours</h3>
 
 Input vector map contains 2D lines representing contours. Height can
-be assign to the contours using tool <b>zbulk</b>. First of all 2D
+be assign to the contours using <b>tool=zbulk</b>. First of all 2D
 lines need to be converted to 3D lines:
 
 <div class="code"><pre>