Update rebuild.sh to not be position dependent

paper-houses-theme/rebuild.sh

@@ -2,6 +2,10 @@
 
 # Should be run as ./rebuild.sh
 
+(
+    # CD to the directory that this file is in
+    cd $(dirname "$0")
+
     if ! command -v sass &> /dev/null
     then
         echo "sass could not be found. Please install sass"
@@ -9,3 +13,4 @@ then
     fi
 
     sass -w assets/styles/main.scss assets/built/main.css
+)