refactor: build only one frappe/erpnext image (#1032)

* ci: skip frappe builds

* refactor: build only one frappe/erpnext image

* fix: lint nginx entrypoint script

* docs: update and organize docs

* docs: fix lint errors

* fix(custom): pass base64 encoded apps json

* ci: update dependabot

* docs: update contributing

* docs: remove info about multi image setup

* fix: initiate empty common_site_config.json

default config has host keys set to localhost
causes connection errors

* docs: add details for pwd volumes

* fix: symlink assets instead of copy

* fix: nginx private files

* ci: skip docker compose v2 install for ubuntu-latest

* fix: organize layers

* feat: allow remove git remote for custom image

* docs: allow remove git remote for custom image

* fix: remove duplicate --apps_path

docs/backup-and-push-cronjob.md

@@ -5,7 +5,7 @@ Create backup service or stack.
 version: "3.7"
 services:
   backup:
-    image: frappe/erpnext-worker:v14
+    image: frappe/erpnext:v14
     entrypoint: ["bash", "-c"]
     command: |
       for SITE in $(/home/frappe/frappe-bench/env/bin/python -c "import frappe;print(' '.join(frappe.utils.get_sites()))")