New plugin submission flow related changes

Author: alex-codefresh

example.yml

@@ -0,0 +1,23 @@
+image: codefreshplugins/cfstep-gitsubmodules
+tag: latest
+version: 0.1.0
+description: Update git submodules
+keywords:
+  - git
+  - submodules
+sources:
+  - https://github.com/codefresh-contrib/cfstep-gitsubmodules
+maintainers:
+  - name: Francisco Cocozza
+    email: francisco@codefresh.io
+icon: https://git-scm.com/images/icons/downloads/Git-Icon-1788C.png
+envs:
+    - name: GITHUB_TOKEN
+      type: required
+      description: GitHub Token required to access the repository
+    - name: CF_SUBMODULE_SYNC
+      type: optional
+      description: if var is set to 'true', the step will perform 'git submodule sync' command
+    - name: CF_SUBMODULE_UPDATE_RECURSIVE
+      type: optional
+      description: if set to 'true', the step will perform 'git submodule update --init' command with '--recursive' option