Fix contributing readme typo

Correct npm run docs:serve for running vue press docs

Signed-off-by: Dixsie Wolmers <[email protected]>
Change-Id: Idd2e54f3f61e06baf46121984e0907989a0f3801

Author: dixsie

CONTRIBUTING.md

@@ -46,7 +46,7 @@ npm run serve
 
 ### Run Documentation Locally (Vuepress static site generation)
 ```
-Run npm docs:serve
+npm run docs:serve
 ```
 
 ### Run unit tests