fix(): Adds step to pull the theme

.drone.yml

@@ -3,9 +3,24 @@ kind: pipeline
 name: default
 
 steps:
+- name: clone
+  image: alpine/git
+  commands:
+   - git submodule update --init --recursive
+  volumes:
+    - name: hugo-cache
+      path: /drone/src
+
 - name: build
   image: plugins/hugo
+  volumes:
+    - name: hugo-cache
+      path: /drone/src
   settings:
     hugo_version: 0.84.4
     validate: true
     pull: always
+
+volumes:
+- name: hugo-cache
+  temp: {}