add pip support and some docs

tasks/main.yml

@@ -1,14 +1,19 @@
 - name: filter package list
   set_fact:
-    pkgs: "{{ packages.pkg | dict2items | rejectattr('value', 'none') | map(attribute='key') | list }}"
+    pkgs_system: "{{ packages.pkg | packages_by_provider(provider='system', defaults=default_packages_pkg) }}"
+    pkgs_pip_system: "{{ packages.pkg | packages_by_provider(provider='pip-system', defaults=default_packages_pkg) }}"
 
 - name: list repositories to setup
   debug:
     var: packages.repos
     verbosity: 1
-- name: list packages to install
+- name: list system packages to install
   debug:
-    var: pkgs
+    var: pkgs_system
+    verbosity: 1
+- name: list pip packages to install
+  debug:
+    var: pkgs_pip_system
     verbosity: 1
 
 - name: install helper tools
@@ -33,6 +38,11 @@
 - name: ensure handlers are flushed
   meta: flush_handlers
 
-- name: install packages
+- name: install packages (system)
   apt:
-    pkg: "{{ pkgs }}"
+    pkg: "{{ pkgs_system }}"
+
+- name: install packages (pip-system)
+  pip:
+    name: "{{ pkgs_pip_system }}"
+    extra_args: "--break-system-packages"