docs fix and upd

docs/index.md

@@ -4,15 +4,17 @@
 
 Starting a documentation site for this project, the main goal is to create docs here as better as possible to help anyone who wants to install or use this Django project, but also this first (an minimal) version of the documentation site was created specially to write about the next release that will support from this commit and up, the basic integration with our another main project, Utopía CRM, both using its default installations and requiering only a few steps of configuration.
 
-So, the next section, will talk about this integration and of course, with the time, this documentation home page will include all the docs that we have now and the many others that we must to create.
+So, the next section, will talk about this integration and of course, with the time, this documentation home page will include all the docs that we have now and the many others that we must create.
+
+TODO: make separated md files for each next `##` and link them here.
 
 ## Utopía CRM integration
 
 This is an skel of steps that we will describe better on next commits, but is a good start point to have an idea on what are the things to do to obtain a deployment of Utopía CMS that can interoperate with a deployment of Utopía CRM.
 
 1. Install both projects, Utopía CRM and CMS, following the INSTALL.md docs in the root of each, and after having both systems up and running with admin access in front-end, and also access to modify the "local settings", continue to next step.
 2. Configure the url of each one in the other:
-    - In CMS `local_settings.py` assign the CMS root url in the setting `LDSOCIAL_URL`, example:
+    - In CRM `local_settings.py` assign the CMS root url in the setting `LDSOCIAL_URL`, example:
 
         ```
         LDSOCIAL_URL = "https://yoogle.com/"
@@ -55,3 +57,21 @@ This is an skel of steps that we will describe better on next commits, but is a
 5. Restart both servers and test the integration creating Users in CMS matching Contacts in CRM with the same email, then for example, when email is changed in one project, the change will be also performed in the other system, take a look also in the `contact_id` field of CMS Subscribers (`thedaily.models.Subscriber.contact_id) this is the "link" metadata with more precedence used by the apis who sync any object with its respective "pair".
 
 We hope have much more documentation in the next commits, for this topic and many others.
+
+## Newsletters
+
+### Intro
+
+TODO: write about what a NL is, how to preview and send
+
+### Default content
+
+The default content of each newsletter can be modified by redefining the template of each newsletter. Additionally, by customizing the available settings for this functionality, many combinations of alternative content can be achieved. Over the years in production, we have made it possible to meet various requirements requested by editorial, sales, management, and other teams.
+
+* Publications:
+
+Featured articles are selected, meaning those that would appear on the publication's cover.
+
+* Areas:
+
+Priority is given to the "area newsletter" object that may exist with valid validity (there is a "valid until" datetime field) for the respective area. If the former is not valid or does not exist, articles from the "area cover" object associated with the respective area are then selected.