Install dependencies before running watchers

Although the Makefile has the required dependencies, once everything is
launched in parallel making the live reloader unavailable as caddy
already launches.

scripts/startdevelop.sh

@@ -2,6 +2,8 @@
 
 SESSION=reprowebsite
 
+make vendor
+
 tmux new-session -d -s ${SESSION}
 
 # Setup panes